Journal articles on the topic 'Fluid flow in DFN'
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1
Zhang, Jing, Richeng Liu, Liyuan Yu, Shuchen Li, Xiaolin Wang, and Ding Liu. "An Equivalent Pipe Network Modeling Approach for Characterizing Fluid Flow through Three-Dimensional Fracture Networks: Verification and Applications." Water 14, no. 10 (May 16, 2022): 1582. http://dx.doi.org/10.3390/w14101582.
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The equivalent pipe network (EPN) model is an effective way to model fluid flow in large-scale fractured rock masses with a complex fracture network due to its straightforwardness and computational efficiency. This study presents the EPN model for characterizing fluid flow through three-dimensional fracture networks using the Monte-Carlo method. The EPN model is extracted from an original three-dimensional discrete fracture network (DFN) model and is used to simulate the fluid flow processes. The validity of the proposed EPN modeling approach is verified via the comparisons of permeability (k) with analytical solutions and simulation results reported in the literature. The results show that the numerically calculated k using EPN models agrees well with the analytical values of simplified DFN models and the simulation results of complex DFN models. The k increases following an exponential function with the increment of mean length of exponentially distributed fractures (u), which is strongly correlated with fracture density (P32) and average intersection length (Li). The P32 increases in an exponential way with the increment of u. The Li increases as u increases, following a power-law function. The increment of u leads to the increment of a number of long fractures in three-dimensional DFN models. A larger u results in a denser fracture network and a stronger conductivity when the number and length distribution range of fractures remain the same. The representative elementary volumes (REVs) of three-dimensional DFN models with u = 9 m and P32 = 0.4 m2/m3 are determined as 2.36 × 104 m3, 9.16 × 103 m3, and 1.26 × 104 m3 in 3 flow directions, respectively.
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Namdari, Sajad, Alireza Baghbanan, and Hamid Hashemolhosseini. "INVESTIGATION OF THE EFFECT OF THE DISCONTINUITY DIRECTION ON FLUID FLOW IN POROUS ROCK MASSES ON A LARGE-SCALE USING HYBRID FVM-DFN AND STREAMLINE SIMULATION." Rudarsko-geološko-naftni zbornik 36, no. 4 (2021): 49–59. http://dx.doi.org/10.17794/rgn.2021.4.5.
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Understanding the fluid behaviour in rock masses is of great importance in various rock mass-related engineering projects, such as seepage in tunnels, geothermal reservoirs, and hazardous waste disposal. Different approaches have been implemented to study the flow pattern in fractured porous rock masses. Laboratory experiments can provide good information regarding this issue, but high expenses aside, they are time-consuming and suffer the lack of ability to study field scale mediums. Numerical methods are beneficial in simulating such mediums with the Discrete Fracture Network (DFN) method in terms of costs and time as they offer sufficient flexibility and creativity. In this paper, a Matlab code was extended to study the flow regime in a Dual Permeability Media (DPM) with two point sources in the right and left side of the model as an injector and a producer well, respectively. A high permeability discontinuity with different angles was embedded in a very low-permeability limestone matrix. Pressure equations were solved implicitly with a two-point flux approximation scheme of the Finite Volume Method (FVM). Streamlines were traced in the medium and used to analyse the model’s hydraulic behaviour with the aid of Time Of Flight (TOF) for each point. The results show that the FVM-DFN hybrid method can be used as a fast method for fluid flow in DPM with the aid of streamline simulation to study the fluid flow in a large model with discontinuity.
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Akara, Mahawa Essa Mabossani, Donald M. Reeves, and Rishi Parashar. "Enhancing fracture-network characterization and discrete-fracture-network simulation with high-resolution surveys using unmanned aerial vehicles." Hydrogeology Journal 28, no. 7 (June 18, 2020): 2285–302. http://dx.doi.org/10.1007/s10040-020-02178-y.
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Abstract A workflow is presented that integrates unmanned aerial vehicle (UAV) imagery with discrete fracture network (DFN) geometric characterization and quantification of fluid flow. The DFN analysis allows for reliable characterization and reproduction of the most relevant features of fracture networks, including: identification of orientation sets and their characteristics (mean orientation, dispersion, and prior probability); scale invariance in distributions of fracture length and spatial location/clustering; and the distribution of aperture values used to compute network-scale equivalent permeability. A two-dimensional DFN-generation approach honors field data by explicitly reproducing observed multi-scale fracture clustering using a multiplicative cascade process and power law distribution of fracture length. The influence of aperture on network-scale equivalent permeability is investigated using comparisons between a sublinear aperture-to-length relationship and constant aperture. To assess the applicability of the developed methodology, DFN flow simulations are calibrated to pumping test data. Results suggest that even at small scales, UAV surveys capture the essential geometrical properties required for fluid flow characterization. Both the constant and sublinear aperture scaling approaches provide good matches to the pumping test results with only minimal calibration, indicating that the reproduced networks sufficiently capture the geometric and connectivity properties characteristic of the granitic rocks at the study site. The sublinear aperture scaling case honors the directions of dominant fractures that play a critical role in connecting fracture clusters and provides a realistic representation of network permeability.
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Wenli, Yao, Mostafa Sharifzadeh, Zhen Yang, Guang Xu, and Zhigang Fang. "Assessment of fracture characteristics controlling fluid flow performance in discrete fracture networks (DFN)." Journal of Petroleum Science and Engineering 178 (July 2019): 1104–11. http://dx.doi.org/10.1016/j.petrol.2019.04.011.
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Shi, Di, Liping Li, Jianjun Liu, Mingyang Wu, Yishan Pan, and Jupeng Tang. "Effect of discrete fractures with or without roughness on seepage characteristics of fractured rocks." Physics of Fluids 34, no. 7 (July 2022): 073611. http://dx.doi.org/10.1063/5.0097025.
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This study proposes a new fractal permeability model for fractured rocks that comprehensively accounts for the geometric fracture characteristics and the fluid transport mechanism. Then, the permeability changes of fractured rocks are analyzed using discrete fracture networks (DFNs) with or without roughness and different geometry parameters in the DFN modeling and finite element simulation. The results show that the proposed permeability model well agrees with the experimental data, and the established DFN numerical model more realistically reflects the fracture network in fractured rocks. Fluctuation of tortuous fracture lines (rough fractures) increases the fracture intersection probability, consequently increasing the fracture intersection area or connecting adjacent fractures. Moreover, permeability increases with the fractal dimension Df, porosity ϕ, maximum fracture length lmax, and proportionality coefficient β, and it decreases with increasing fractal dimension DTf of fracture tortuosity. When the fracture proportionality coefficient is 0.001 ≤ β ≤ 0.01, different DFNs yield similar simulation results for permeability. However, with increasing fracture network complexity, the predictive model created using conventional DFN (C-DFN) increasingly overestimates the fractured rock permeability. Thus, building a permeability model for a fractured rock using rough DFN (R-DFN) is more effective than that using C-DFN. Our findings are helpful for real permeability predictions via DFN and analytical modeling.
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Alvarez, Leidy Laura, Leonardo José do Nascimento Guimarães, Igor Fernandes Gomes, Leila Beserra, Leonardo Cabral Pereira, Tiago Siqueira de Miranda, Bruno Maciel, and José Antônio Barbosa. "Impact of Fracture Topology on the Fluid Flow Behavior of Naturally Fractured Reservoirs." Energies 14, no. 17 (September 2, 2021): 5488. http://dx.doi.org/10.3390/en14175488.
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Fluid flow modeling of naturally fractured reservoirs remains a challenge because of the complex nature of fracture systems controlled by various chemical and physical phenomena. A discrete fracture network (DFN) model represents an approach to capturing the relationship of fractures in a fracture system. Topology represents the connectivity aspect of the fracture planes, which have a fundamental role in flow simulation in geomaterials involving fractures and the rock matrix. Therefore, one of the most-used methods to treat fractured reservoirs is the double porosity-double permeability model. This approach requires the shape factor calculation, a key parameter used to determine the effects of coupled fracture-matrix fluid flow on the mass transfer between different domains. This paper presents a numerical investigation that aimed to evaluate the impact of fracture topology on the shape factor and equivalent permeability through hydraulic connectivity (f). This study was based on numerical simulations of flow performed in discrete fracture network (DFN) models embedded in finite element meshes (FEM). Modeled cases represent four hypothetical examples of fractured media and three real scenarios extracted from a Brazilian pre-salt carbonate reservoir model. We have compared the results of the numerical simulations with data obtained using Oda’s analytical model and Oda’s correction approach, considering the hydraulic connectivity f. The simulations showed that the equivalent permeability and the shape factor are strongly influenced by the hydraulic connectivity (f) in synthetic scenarios for X and Y-node topological patterns, which showed the higher value for f (0.81) and more expressive values for upscaled permeability (kx-node = 0.1151 and ky-node = 0.1153) and shape factor (25.6 and 14.5), respectively. We have shown that the analytical methods are not efficient for estimating the equivalent permeability of the fractured medium, including when these methods were corrected using topological aspects.
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WANG, XIAOSHAN, YUJING JIANG, RICHENG LIU, BO LI, and ZAIQUAN WANG. "A NUMERICAL STUDY OF EQUIVALENT PERMEABILITY OF 2D FRACTAL ROCK FRACTURE NETWORKS." Fractals 28, no. 01 (February 2020): 2050014. http://dx.doi.org/10.1142/s0218348x20500140.
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This paper presents a numerical study on the equivalent permeability of a fractured rock. A series of two-dimensional discrete fracture network (DFN) models for the calculation of equivalent permeability are generated based on discrete element method (DEM). A sufficient large “parent” DFN model is generated based on the data obtained from a site investigation result of Three Gorges Project in China. Smaller DFN models are extracted from the large “parent” DFN model to calculate the equivalent permeability with an interval of rotation angle of [Formula: see text]. Fluid flow through fractures in both horizontal and vertical directions is simulated. The results show that when the side length of DFN models are larger than 40[Formula: see text]m, the equivalent permeability of both [Formula: see text] and [Formula: see text] become stable, indicating that a DFN model size of 40[Formula: see text]m can be approximated as a representative elementary volume (REV) for those studied rocks. Penetration ellipses are fitted using the least square method on the basis of the calculated equivalent permeability tensor and the main seepage directions of this fractured rock were determined as 63–67[Formula: see text]. Fractal characteristics of DFN models are analyzed with box-counting method by changing the fracture trace length and fracture density, and the results show that equivalent permeability exhibits a logarithmic increasing trend with the increment of fractal dimension.
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Massaro, L., A. Corradetti, F. Vinci, S. Tavani, A. Iannace, M. Parente, and S. Mazzoli. "Multiscale Fracture Analysis in a Reservoir-Scale Carbonate Platform Exposure (Sorrento Peninsula, Italy): Implications for Fluid Flow." Geofluids 2018 (2018): 1–10. http://dx.doi.org/10.1155/2018/7526425.
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We derive the discrete fracture network (DFN) of a Lower Cretaceous carbonate platform succession exposed at Mt. Faito (Southern Apennines), which represents a good outcrop analogue of the coeval productive units of the buried Apulian Platform in the Basilicata oilfields. A stochastic distribution of joints has been derived by sampling at two different scales of observation. At the outcrop scale, we measured fracture attributes by means of scan lines. At a larger scale, we extracted fracture attributes from a 3D model. This multiscale survey showed the occurrence of an arresting bed for through-going fractures, which is characterized by a low relative permeability, determining a vertical compartmentalization. The DFN model, obtained by integrating fieldwork and numerical modelling by means of the 3D-Move® software, shows a well-defined relationship of permeability and fracture porosity with the relative connectivity of the fracture network. The latter is influenced by the length and aperture and to a lesser extent by the fracture intensity. The permeability distribution obtained for our outcrop analogue can be used to inform modelling of the Basilicata oilfield reservoirs, although the different burial history between the exposed Apennine Platform and the buried Apulian Platform must be taken into account.
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Kurison, Clay, and Huseyin S. Kuleli. "Matrix permeability and flow-derived DFN constrain reactivated natural fracture rupture area and stress drop — Marcellus Shale microseismic example." Leading Edge 40, no. 9 (September 2021): 667–76. http://dx.doi.org/10.1190/tle40090667.1.
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Microseismic events associated with shale reservoir hydraulic fracturing stimulation (HFS) are interpreted to be reactivations of ubiquitous natural fractures (NFs). Despite adoption of discrete fracture network (DFN) models, accounting for NFs in fluid flow within shale reservoirs has remained a challenge. For an explicit account of NFs, this study introduced the use of seismology-based relations linking seismic moment, moment magnitude, fault rupture area, and stress drop. Microseismic data from HFS monitoring of Marcellus Shale horizontal wells had been used to derive planar hydraulic fracture geometry and source properties. The former was integrated with associated well production data found to exhibit transient linear flow. Analytical solutions led to linear flow parameters (LFPs) and system permeability for scenarios depicting flow through infinite and finite conductivity hydraulic fractures. Published core plug permeability was stress-corrected for in-situ conditions to estimate average matrix permeability. For comparison, the burial and thermal history for the study area was used in 1D Darcy-based modeling of steady and episodic expulsion of petroleum to account for geologic timescale persistence of abnormal pore pressure. Both evaluations resulted in matrix permeability in the same picodarcy (pD) range. Coupled with LFPs, reactivated NF surface area for stochastic DFNs was estimated. Subsequently, the aforementioned seismology-based relations were used for determining average stress drops needed to estimate NF rupture area matching flow-based DFN surface areas. Stress drops, comparable to values for tectonic events, were excluded. One of the determined values matched stress drops for HFS operations in past and recent seismological studies. In addition, calculated changes in pore pressure matched estimates in the aforementioned studies. This study unlocked the full potential of microseismic data beyond extraction of planar geometry attributes and stimulated reservoir volume (SRV). Here, microseismic events were explicitly used in the quantitative account of NFs in fluid flow within shale reservoirs.
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Liu, Ding, Hai Pu, Shiru Guo, Ziheng Sha, and Chong Li. "Numerical Investigations on the Effect of Fracture Length Distribution on the Representative Elementary Volume of 3D Discrete Fracture Networks." Geofluids 2022 (June 9, 2022): 1–16. http://dx.doi.org/10.1155/2022/8073013.
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Determination of the representative elementary volume (REV) of fractured rock masses based on equivalent permeability ( K ) is significantly dependent on the geometric characteristics of fractures. In this work, a series of numerical simulations were performed to analyze the relationship between geometric characteristics of fractures and the REV size, in which fracture length follows a power-law distribution. A method to evaluate the K of a three-dimensional (3D) discrete fracture network (DFN) by extracting the equivalent pipe network (EPN) model from the DFN model was utilized and verified. The results show that K of the 3D DFN model has an exponential relationship with the power exponent ( a ) of fracture length distribution and the evaluation of K agrees well with that reported in previous studies, confirming the reliability of the EPN model for calculating seepage properties of complex 3D DFN models. When the side length of submodels ( L n ) is small, the K varies significantly due to the influence of random number seeds used to generate fracture length, location, and orientation. The K holds a constant value after L n exceeds some specific value. The critical model scale is determined as the REV size, and the corresponding volume of the 3D DFN model is represented by V REV . The V REV varies within a narrow range when a ≤ 4.0 . When a = 4.5 , the V REV rapidly increases to more than 3.4 times than that when a = 4.0 . The fluid flow becomes more inhomogeneous due to the small nonpersistent fractures that dominate the preferential flow paths when a exceeds a certain value (i.e., 4.5). The K at the REV size decreases exponentially with the increment of a . This tendency can be explained by the decrease of the average intersection length ( L i ) with the increment of a , which is a geometric parameter for reflecting the connectivity of the fracture network.
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Pan, Bin, and Yang Song Zhang. "Searching for the Shortest Seepage Path of 3D Network in Fractured Rock Masses." Applied Mechanics and Materials 580-583 (July 2014): 857–61. http://dx.doi.org/10.4028/www.scientific.net/amm.580-583.857.
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Fractured rock is a combination of rocks and fractures,the fractures which are ubiquitously distributed in fractured rock mass often constitute the flow and migration path of underground fluid and radionuclide.Discrete Fracture Network Model (DFN) was built with in-situ observations to evaluate the hydraulic conductivity tensor of rock masses.The fractures relation pattern with corresponding algorithm is given on the basis of computational geometric,and then the graph theory is employed as the mathematical model to represent the mutual positional relation of fractures.And then,with the use of Dijkstra algorithm, the hydraulic conductivity tensor could be obtained.
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Hosseini, Erfan, Mohammad Sarmadivaleh, and Zhongwei Chen. "Developing a new algorithm for numerical modeling of discrete fracture network (DFN) for anisotropic rock and percolation properties." Journal of Petroleum Exploration and Production Technology 11, no. 2 (January 22, 2021): 839–56. http://dx.doi.org/10.1007/s13202-020-01079-w.
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AbstractThe role of natural fractures in future reservoir performance is prominent. The fractured porous media is composed of an interconnected network of fractures and blocks of the porous medium where fractures occur in various scales and have a strong influence either when most of the flow is concentrated and them or when they act as barriers. A general numerical model for discrete fracture networks (DFN) is usually employed to handle the observed wide variety of fracture properties and the lack of direct fracture visualization. These models generally use fracture properties’ stochastic distribution based on sparse and seismic data without any physical model constraint. Alternatively, a DFN model includes usual numerical geomechanical approaches like boundary element and finite element. But here, a geostatistical methodology has been used to generate a DFN model. In this paper, an alternative modeling technique is employed to create the realization of an anisotropic fractured rock using simulated annealing (SA) optimization algorithm. There is a notable positive correlation between fracture length and position. There are three principal subjects in a study of fractured rocks. Firstly, the network’s connectivity, secondly, fluid flows through the system, and thirdly, dispersion. Here, connectivity of generated networks is considered. Continuum percolation is the mathematical model to study the geometry of connected components in a random subset of space. Different random realizations from the S.A. algorithm in four different sizes of L = 100, 150, 200, 250 at post-threshold condition are used as disordered media in percolation theory to compute percolation properties using Monte Carlo simulation. The percolation threshold (critical fracture density) and two crucial scaling exponents (β and υ) that dictate the model’s connectivity behavior are estimated to over 200 realizations.
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Williams-Stroud, Sherilyn, Chet Ozgen, and Randall L. Billingsley. "Microseismicity-constrained discrete fracture network models for stimulated reservoir simulation." GEOPHYSICS 78, no. 1 (January 1, 2013): B37—B47. http://dx.doi.org/10.1190/geo2011-0061.1.
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The effectiveness of hydraulic fracture stimulation in low-permeability reservoirs was evaluated by mapping microseismic events related to rock fracturing. The geometry of stage by stage event point sets were used to infer fracture orientation, particularly in the case where events line up along an azimuth, or have a planar distribution in three dimensions. Locations of microseismic events may have a higher degree of uncertainty when there is a low signal-to-noise ratio (either due to low magnitude or to propagation effects). Low signal-to-noise events are not as accurately located in the reservoir, or may fall below the detectability limit, so that the extent of fracture stimulated reservoir may be underestimated. In the Bakken Formation of the Williston Basin, we combined geologic analysis with process-based and stochastic fracture modeling to build multiple possible discrete fracture network (DFN) model realizations. We then integrated the geologic model with production data and numerical simulation to evaluate the impact on estimated ultimate recovery (EUR). We tested assumptions used to create the DFN model to determine their impact on dynamic calibration of the simulation model, and their impact on predictions of EUR. Comparison of simulation results, using fracture flow properties generated from two different calibrated DFN scenarios, showed a 16% difference in amount of oil ultimately produced from the well. The amount of produced water was strongly impacted by the geometry of the DFN model. The character of the DFN significantly impacts the relative amounts of fluids produced. Monitoring water cut with production can validate the appropriate DFN scenario, and provide critical information for the optimal method for well production. The results indicated that simulation of enhanced permeability using induced microseismicity to constrain a fracture flow property model is an effective way to evaluate the performance of reservoirs stimulated by hydraulic fracture treatments.
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Noya, Mesak Frits, Rusdy Rumeon, P. W. Tetelepta, and Abdul Hadi. "KINERJA POMPA JET EJECTOR DENGAN MODIFIKASI HELMHOLTZ RESONATOR PADA PIPA NORMAL SHOCK." ARIKA 15, no. 2 (August 31, 2021): 94–103. http://dx.doi.org/10.30598/arika.2021.15.2.94.
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Setiap fluida yang mengalir selalu memiliki bunyi dengan intensitas dan frekwensi tertentu di dalam atau diluar ambang batas audio. Sifat akustik dari aliran fluida ini menjadi ide untuk memodifikasi normal shock diffuser dari suatu sistem fluida dengan menerapkan helmholtz resonator sebagai pengganti normal shock diffuser dengan menggabungkan dua pompa yang di aliri fluida, yaitu pompa sentrifugal tekanan rendah berkapasitas tinggi dan pompa injeksi tekanan tinggi berkapasitas rendah. Penelitian ini bertujuan untuk menentukan berapa besar pengaruh variasi jumlah pipa kapiler helmholtz resonator terhadap kinerja aliran fluida hidrolik booster-jet ejector pump. Penelitian ini bersifat eksperimental, dengan menerapkan sensor magneto flow meter arduino mega untuk mengukur kapasitas aliran fluida. Hasil penelitian ini menunjukan daya terbesar berada pada helmholtz resonator dengan jumlah 4 pipa kapiler yaitu sebesar 170,914353 Watt. Disimpulkan bahwa kinerja pompa jet-ejector mengalami peningkatan sebesar 36% dari daya sebesar 125 Watt sebelum modifikasi.
Kata Kunci : Booster Jet Ejector, Resonator Helmholtz, Normal Shock
Every fluid that flows always has a sound with a certain intensity and frequency, within or outside the audio threshold. The acoustic properties of this fluid flow became the idea to modify the normal shock diffuser of a fluid system by applying a Helmholtz resonator as a substitute for the normal shock diffuser by combining two pumps that are fed with fluid entering through a high-capacity low-pressure centrifugal pump and the other pump namely high pressure -low capacity injection pump. This study aims to determine how much the variation in the number of Helmholtz resonator capillaries towards performance of the hydraulic fluid flow of the booster-jet ejector pump. This research is experimental, by applying the arduino mega magneto flow meter sensor to measure the fluid flow capacity. The results of this study show that the greatest power is in the helmholtz resonator with a total of 4 capillary pipes, which is 170.914353 Watt. It is concluded that the performance of the jet-ejector pump has increased by 36% from the power of 125 Watt before modification.
Keywords: Booster Jet Ejector, Helmholtz Resonator, Normal Shock
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Syukran, Syukran. "Kaji efisiensi temperatur penukar panas dengan variasi aliran untuk aplikasi pengering." Jurnal POLIMESIN 16, no. 2 (August 30, 2018): 39. http://dx.doi.org/10.30811/jpl.v16i2.562.
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Abstrak Heat exchanger atau alat penukar panas adalah alat-alat yang digunakan untuk mengubah temperatur fluida atau mengubah fasa fluida dengan cara mempertukarkan panasnya dengan fluida lain. Pada sebuah penukar panas kemampuan mempertukarkan panas sangat ditentukan oleh tipe dan jenis aliran fluida yang melewati penukar panas. Secara garis besar penukar panas dibagi berdasarkan arah aliran fluidanya. Berdasarkan arah aliran fluida penukar panas dibedakan menjadi 3 (tiga) jenis aliran, yaitu aliran searah (parallel flow), aliran berlawanan (counter flow) dan aliran silang (cross flow). Saat ini penukar panas banyak dipakai dalam industri pengeringan produk-produk pertanian, perkebunan dan perikanan skala kecil dan menengah. Penggunaan penukar panas dalam bidang pengeringan saat ini sudah menjadi kebutuhan untuk mengatasi permasalahan produktifitas pengeringan. Umumnya penukar panas yang digunakan adalah tipe aliran berlawanan. Beberapa penelitian telah dilakukan untuk mengetahui efektifitas penukar panas tersebut yang umumnya berfokus pada jenis aliran berlawanan. Penelitian penelitian spesifik yang mengkaji perbandingan efisiensi penukar panas untuk ketiga jenis aliran belum ditemukan. Penelitian ini dilakukan untuk mengetahui efisiensi temperatur penukar panas untuk jenis aliran jenis aliran melintang, sejajar, dan berlawanan. Metode penelitian dilakukan fabrikasi 3 unit exchanger tipe gas-gas dengan dimensi 50 (P) x 10 (L) x 30 (T) dengan jumlah tube 17 susunan. Hasil penelitian menunjukkan bahwa efisiensi temperatur untuk ketiga jenis penukar panas tersebut adalah 21,3% aliran melintang, 17,3% aliran berlawanan dan 15,9% aliran sejajar. Hasil penelitian menyimpulkan bahwa efisiensi temperatur tertinggi diperoleh jenis penukar panas aliran melintang. Kata kunci : Penukar panas, aliran sejajar, aliran berlawanan, aliran silang, temperatur. Abstrack Heat exchangers or heat exchangers are the means used to change the temperature of the fluid or to change the fluid phase by exchanging heat with other fluids. In a heat exchanger the heat exchange ability is greatly determined by the type and type of fluid flow passing through the heat exchanger. Broadly speaking the exchanger is divided based on the direction of fluid flow. Based on the direction of fluid flow exchanger is divided into 3 (three) types of flow, namely parallel flow, counter flow and cross flow. Currently, heat exchangers are widely used in the drying industry of small and medium-sized agricultural and small-scale plantation and fishery products. The use of exchangers in the field of drying is now a need to overcome the problems of drying productivity. Generally the exchanger used is the opposite flow type (counter flow). Several studies have been conducted to determine the effectiveness of these exchangers which generally focus on the opposite type of flow. Specific research studies that reviewed the efficiency of exchangers for the three types of flow have not been found. This research was conducted to find out the efficiency of heat exchanger temperature for flow type of cross flow, parallel flow and counter flow type. The research method was fabricated 3 units of gas-gas exchanger type with dimension 50 (P) x 10 (L) x 30 (T) with the number of tubes 17 staggered arrangement. The results show that the temperature efficiency for the three types of heat exchanger is 21.3% cross flow flow, 17.3% flow counter flow and 15.9% parallel flow flow. The results concluded that the highest temperature efficiency obtained by cross flow flow type exchanger. Keywords: Heat exchanger, parallel flow, counter flow, cross flow, temperature
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Li, Ang, Yaodong Li, Feng Wu, Guojian Shao, and Yang Sun. "Simulation Method and Application of Three-Dimensional DFN for Rock Mass Based on Monte-Carlo Technique." Applied Sciences 12, no. 22 (November 10, 2022): 11385. http://dx.doi.org/10.3390/app122211385.
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In this study, the authors simulate a polygonal discrete fracture network (DFN) in rock masses. The probability models of the relevant geological parameters, including the orientation, trace length, volume density, and coordinates of the centroid, are firstly developed as fractures are in the shape of rectangles. In the process, the probability distribution of rectangular fractures with side lengths as random variables is introduced and described in terms of mean trace lengths on the basis of the probability model of disk-shaped fracture with the diameter as the random variable. The relationship between the volume density and the linear density of rectangular fractures is given for a negative exponential distribution. Following this, the coordinates of the vertices of fractures are derived based on spatial algebraic geometry, and the data for the three-dimensional DFN model are generated using the Monte-Carlo technique. The resulting three-dimensional DFN is visualized by calling the Open GL graphics database in the environment of Visual C, and the process of implementation of the DFN simulation is given. Finally, the validity of the simulation is verified by applying it to engineering practice.
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Yu, Yun-Chen, I.-Hsien Lee, Chuen-Fa Ni, Yu-Hsiang Shen, Cong-Zhang Tong, Yuan-Chieh Wu, and Emilie Lo. "Numerical Assessment of the Hybrid Approach for Simulating Three-Dimensional Flow and Advective Transport in Fractured Rocks." Applied Sciences 11, no. 22 (November 15, 2021): 10792. http://dx.doi.org/10.3390/app112210792.
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This study presents a hybrid approach for simulating flow and advective transport dynamics in fractured rocks. The developed hybrid domain (HD) model uses the two-dimensional (2D) triangular mesh for fractures and tetrahedral mesh for the three-dimensional (3D) rock matrix in a simulation domain and allows the system of equations to be solved simultaneously. This study also illustrates the HD model with two numerical cases that focus on the flow and advective transport between the fractures and rock matrix. The quantitative assessments are conducted by comparing the HD results with those obtained from the discrete fracture network (DFN) and equivalent continuum porous medium (ECPM) models. Results show that the HD model reproduces the head solutions obtained from the ECPM model in the simulation domain and heads from the DFN model in the fractures in the first case. The particle tracking results show that the mean particle velocity in the HD model can be 7.62 times higher than that obtained from the ECPM mode. In addition, the developed HD model enables detailed calculations of the fluxes at intersections between fractures and cylinder objects in the case and obtains relatively accurate flux along the intersections. The solutions are the key factors to evaluate the sources of contaminant released from the disposal facility.
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Li, Xinxin, Dianqing Li, Yi Xu, and Xiaobo Feng. "A DFN based 3D numerical approach for modeling coupled groundwater flow and solute transport in fractured rock mass." International Journal of Heat and Mass Transfer 149 (March 2020): 119179. http://dx.doi.org/10.1016/j.ijheatmasstransfer.2019.119179.
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Saleh, Muhammad Marzuky, and Edi Widodo. "Analisa Kinerja Aliran Fluida dalam Rangkaian Seri dan Paralel dengan Penambahan Tube Bundle pada Pompa Sentrifugal." R.E.M. (Rekayasa Energi Manufaktur) Jurnal 3, no. 2 (May 2, 2019): 71. http://dx.doi.org/10.21070/r.e.m.v3i2.1884.
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Pump is a device used to move fluid from one place to another through the pipe media as a channel. The pump has 2 important components in its performance, namely: Impeller and pump house (casing). When the pump cannot meet the required capacity it can use series and parallel pump circuits to increase it. When moving the fluid to a high surface or high pressure it will have the specifications of the head and discharge. Fluid flow is a liquid that flows in a pipe. In flow there is fluid pressure and also flow type. There are 3 flow types, namely laminer, transition, turbulent. To reduce turbulence in the flow can be used Tube bundle which is a device consisting of several pipes that are tied together that are attached to a cross section in the pipe. This research was conducted in 4 testing stages, namely series circuit with additional tube bundle, series circuit without additional tube bundle, parallel circuit with additional tube bundle, parallel circuit without additional tube bundle. Each test takes fluid pressure, discharge, flow type. From the results of this study it was found that the parallel circuit pump with an additional tube bundle produces fluid pressure, discharge, flow velocity smaller than the series circuit, whereas when without additional the parallel tube pump bundle produces a fluid pressure, discharge, flow velocity greater than the circuit series, while for the flow type of this study is turbulent flow.
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Kayana, I. Made Dwi, I. Nyoman Pasek Nugraha, and Kadek Rihendra Dantes. "ANALISIS PENGARUH LAJU ALIRAN FLUIDA AIR PADA SALURAN PIPA AIR HANDLING UNIT (AHU) TERHADAP CAPAIAN SUHU OPTIMUM MESIN PENDINGIN MINI WATER CHILER." Jurnal Pendidikan Teknik Mesin Undiksha 6, no. 3 (December 1, 2018): 129. http://dx.doi.org/10.23887/jjtm.v6i3.18588.
Full textAbstract:
Penelitian ini bertujuan untuk mengetahui variasi laju aliran fluida air terhadap capaian suhu optimal mesin pendingin Mini Water Chiler yang di hasilkan pada siklus sekunder. Adapun variasi laju aliran fluida air yang digunakan yaitu variasi laju aliran air 0,27 liter/detik, 0,55 liter/detik, dan 0,83 liter/detik. Teknik analisis data pada penelitian ini menggunakan analisis variasi satu jalur. Pengumpulan data pada penelitian ini dilakukan setiap 20 menit sebanyak 20 kali. Dari hasil penelitian didapatkan penggunakan variasi laju aliran fluida air 0,27 liter/detik,0,55 liter/detik, dan 0,83 liter/detik pada AHU 1 adalah 26,430C : 19,330C : 13,430C. Pada AHU 2 adalah 26,330C : 19,22 0C : 13,330C. Pada AHU 3 adalah 26,230C : 19,120C : 13,230C. Dari pengujian di atas didapatkan penggunaan laju aliran fluida air 0,83 liter/detik menghasilkan suhu paling optimal dibandingkan dengan laju aliran fluida air 0,27 liter/detik dan 0,55 liter/detik, hal ini disebabkan semakin cepat laju aliran fluida air maka semakin optimal suhu yang di capai Mini Water Chiller dan penyerapan panas pada setiap ruangan akan menjadi maksimal.Kata Kunci : Water Chiller, Laju Aliran Fluida, Capaian Suhu Optimal This study tries to study the variation of air fluid flow to the optimal temperature of Mini Water Chiler cooling machines produced in the secondary cycle. The variations in the air flow rate of the air used are variations in air flow rates of 0.27 liters / second, 0.55 liters / second, and 0.83 liters / second. The data analysis technique in this study uses one-way variation analysis. Data collection in this study was carried out every 20 minutes 20 times. From the results of the study obtained using variations in air fluid flow rate 0.27 liters / second, 0.55 liters / second, and 0.83 liters / second in AHU 1 is 26.430C: 19.330C: 13.430C. In AHU 2 is 26.330C: 19.22 0C: 13.330C. In AHU 3 is 26.230C: 19.120C: 13.230C. The water flow of 0.83 liters / second produces an optimal flow of water fluid 0.27 liters / second and 0.55 liters / second, this results in increased fluid flow velocity then the optimal temperature achieved by the Mini Water Chiller and heat at each the room will be maximal.keyword : Mini Water Chiler, Fluid Flow Rate, Optimal Temperatur Achievement
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., I. MADE DWI KAYANA, Dr I. Nyoman Pasek Nugraha, S. T. ,. M. T. ., and Dr Kadek Rihendra Dantes, S. T. ,. M. T. . "ANALISIS PENGARUH LAJU ALIRAN FLUIDA AIR PADA SALURAN PIPA AIR HANDLING UNIT (AHU) TERHADAP CAPAIAN SUHU OPTIMUM MESIN PENDINGIN MINI WATER CHILER." Jurnal Pendidikan Teknik Mesin Undiksha 7, no. 1 (July 17, 2019): 43. http://dx.doi.org/10.23887/jjtm.v7i1.18587.
Full textAbstract:
Penelitian ini bertujuan untuk mengetahui variasi laju aliran fluida air terhadap capaian suhu optimal mesin pendingin Mini Water Chiler yang di hasilkan pada siklus sekunder. Adapun variasi laju aliran fluida air yang digunakan yaitu variasi laju aliran air 0,27 liter/detik, 0,55 liter/detik, dan 0,83 liter/detik. Teknik analisis data pada penelitian ini menggunakan analisis variasi satu jalur. Pengumpulan data pada penelitian ini dilakukan setiap 20 menit sebanyak 20 kali. Dari hasil penelitian didapatkan penggunakan variasi laju aliran fluida air 0,27 liter/detik,0,55 liter/detik, dan 0,83 liter/detik pada AHU 1 adalah 26,430C : 19,330C : 13,430C. Pada AHU 2 adalah 26,330C : 19,22 0C : 13,330C. Pada AHU 3 adalah 26,230C : 19,120C : 13,230C. Dari pengujian di atas didapatkan penggunaan laju aliran fluida air 0,83 liter/detik menghasilkan suhu paling optimal dibandingkan dengan laju aliran fluida air 0,27 liter/detik dan 0,55 liter/detik, hal ini disebabkan semakin cepat laju aliran fluida air maka semakin optimal suhu yang di capai Mini Water Chiller dan penyerapan panas pada setiap ruangan akan menjadi maksimal.Kata Kunci : Water Chiller, Laju Aliran Fluida, Capaian Suhu Optimal This study tries to study the variation of air fluid flow to the optimal temperature of Mini Water Chiler cooling machines produced in the secondary cycle. The variations in the air flow rate of the air used are variations in air flow rates of 0.27 liters / second, 0.55 liters / second, and 0.83 liters / second. The data analysis technique in this study uses one-way variation analysis. Data collection in this study was carried out every 20 minutes 20 times. From the results of the study obtained using variations in air fluid flow rate 0.27 liters / second, 0.55 liters / second, and 0.83 liters / second in AHU 1 is 26.430C: 19.330C: 13.430C. In AHU 2 is 26.330C: 19.22 0C: 13.330C. In AHU 3 is 26.230C: 19.120C: 13.230C. The water flow of 0.83 liters / second produces an optimal flow of water fluid 0.27 liters / second and 0.55 liters / second, this results in increased fluid flow velocity then the optimal temperature achieved by the Mini Water Chiller and heat at each the room will be maximal.keyword : Mini Water Chiler, Fluid Flow Rate, Optimal Temperatur Achievement
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Kayana, Made Dwi, I. Nyoman Pasek Nugraha, and Kadek Rihendra Dantes. "ANALISA PENGARUH LAJU ALIRAN FLUIDA AIR PADA SALURAN PIPA AHU (AIR HANDLING UNIT) TERHADAP CAPAIAN SUHU OPTIMUM MESIN PENDINGIN MINI WATER CHILER." Jurnal Pendidikan Teknik Mesin Undiksha 7, no. 3 (November 29, 2019): 129. http://dx.doi.org/10.23887/jptm.v7i3.26517.
Full textAbstract:
Penelitian ini Penelitian ini bertujuan untuk mengetahui variasi laju aliran fluida air terhadap capaian suhu optimal mesin pendingin Mini Water Chiler yang di hasilkan pada siklus sekunder. Adapun variasi laju aliran fluida air yang digunakan yaitu variasi laju aliran air 0,27 liter/detik, 0,55 liter/detik, dan 0,83 liter/detik..pengumpulan data pada penelitian ini dilakukan setiap 20 menit sebanyak 20 kali. Dari hasil penelitian didapatkan penggunakan variasi laju aliran fluida air 0,27 liter/detik,0,55 liter/detik, dan 0,83 liter/detik pada AHU 1 adalah 26,430C : 19,330C : 13,430C. Pada AHU 2 adalah 26,330C : 19,22 0C : 13,330C. Pada AHU 3 adalah 26,230C : 19,120C : 13,230C. Dari pengujian di atas didapatkan penggunaan laju aliran fluida air 0,83 liter/detik menghasilkan suhu paling optimal dibandingkan dengan laju aliran fluida air 0,27 liter/detik dan 0,55 liter/detik, hal ini disebabkan semakin cepat laju aliran fluida air maka semakin optimal suhu yang di capai Mini Water Chiller dan penyerapan panas pada setiap ruangan akan menjadi maksimal.Kata Kunci : Mini Water Chiler, Laju Aliran Fluida, Capaian Suhu OptimalThis study tries to study the variation of air fluid flow to the optimal temperature of Mini Water Chiler cooling machines produced in the secondary cycle. The variations in the air flow rate of the air used are variations in air flow rates of 0.27 liters / second, 0.55 liters / second, and 0.83 liters / second. The data analysis technique in this study uses one-way variation analysis. Data collection in this study was carried out every 20 minutes 20 times. From the results of the study obtained using variations in air fluid flow rate 0.27 liters / second, 0.55 liters / second, and 0.83 liters / second in AHU 1 is 26.430C: 19.330C: 13.430C. In AHU 2 is 26.330C: 19.22 0C: 13.330C. In AHU 3 is 26.230C: 19.120C: 13.230C. The water flow of 0.83 liters / second produces an optimal flow of water fluid 0.27 liters / second and 0.55 liters / second, this results in increased fluid flow velocity then the optimal temperature achieved by the Mini Water Chiller and heat at each the room will be maximal.Keywords: Mini Water Chiler, Fluid Flow Rate, Optimal Temperatur Achievement
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Ding, D. Y., N. Farah, B. Bourbiaux, Y. S. S. Wu, and I. Mestiri. "Simulation of Matrix/Fracture Interaction in Low-Permeability Fractured Unconventional Reservoirs." SPE Journal 23, no. 04 (March 19, 2018): 1389–411. http://dx.doi.org/10.2118/182608-pa.
Full textAbstract:
Summary Unconventional reservoirs, such as shale-gas or tight oil reservoirs, are generally highly fractured (including hydraulic fractures and stimulated and nonstimulated natural fractures of various sizes) and embedded in low-permeability formations. One of the main production mechanisms in unconventional reservoirs is the flow exchange between matrix and fracture media. However, because of extremely low matrix permeability, the matrix/fracture exchange is very slow and the transient flow may last several years to tens of years, or almost the entire production life. The commonly used dual-porosity (DP) modeling approach involves a computation of pseudosteady-state matrix/fracture transfers with homogenized fluid and flow properties within the matrix medium. This kind of model clearly fails to handle the long-lasting matrix/fracture interaction in very-low-permeability reservoirs, especially for multiphase flow with phase-change problems. Moreover, a DP model is not adapted for the simulation of matrix/fracture exchange when fractures are described by a discrete-fracture network (DFN). This paper presents an embedded discrete-fracture model (EDFM) dependent on the multiple-interacting-continua (MINC) proximity function to overcome this insufficiency of the conventional DP model.
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Yufita, Evi, Muhammad Isa, and Aztarina Ermy Vijaya. "Study of Water Chemical Compounds at Geothermal Area: Case on Geothermal Weh Island, Jaboi." Journal of Aceh Physics Society 9, no. 1 (January 31, 2020): 20–25. http://dx.doi.org/10.24815/jacps.v9i1.15229.
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Kandungan senyawa kimia air sangat berguna dalam penentuan karakteristik fluida panas bumi terutama sumbernya dan arah aliran fluida tersebut. Oleh karena itu dilakukan penelitian untuk mengkaji senyawa kimia air yang terkandung pada lapangan panas bumi. Penelitian ini dilakukan dengan metode Titrasi dan Spektrofotometer Serapan Atom (SSA). Pengambilan sampel air dilakukan di dua lokasi mata air panas. Untuk pengujian sampel dilakukan pada Balai Riset dan Standarisasi (Baristan) Banda Aceh. Pengolahan data dilakukan dengan perbandingan kandungan kimia air, sedangkan interpretasi menggunakan diagram segitiga Ternary. Diagram segitiga ini meliputi Cl-SO4-HCO3, digunakan untuk mengetahui kandungan fuida panas bumi, Cl-Li-B digunakan untuk menentukan temperatur suatu lokasi panasbumi dan Na-K-Mg untuk mengetahui kesetimbangan lingkungan fluida panas bumi. Hasil analisis senyawa kimia air menunjukkan bahwa fluida panas bumi memiliki konsentrasi yang didominasi sulfat SO4, Adapun nilai konsentrasi sulfat masing-masing 95% sampel I dan 97% sampel II. Kandungan kimia air ini diperkirakan berada pada zona upflow. Fluida panas bumi yang muncul ke permukaan dari dua lokasi sampel bersumber langsung dari aktivitas magma. An analysis of the flow of geothermal fluid has been carried out in the Jaboi geothermal field, Sabang. This study aims to obtain a zone of geothermal fluid flow in relation to faults/faults. This research was conducted by the titration method and Atomic Absorption Spectrophotometer (AAS). Sampling was carried out at two hot spring locations, namely crater I and crater IV. For sample testing carried out in a standardized laboratory. Data processing is done through comparison of chemical fluid content and interpretation of Ternary triangle diagrams. The triangle diagram includes Cl-SO4-HCO3, Cl-Li-B and Na-K-Mg to determine the characteristics of geothermal fluids. Based on data that has been processed and correlated with other supporting data (local geological conditions, magnetic, and temperature) shows a relationship that affects each other with the presence of faults. The analysis shows that geothermal fluid in the upflow zone is characterized by a dominant SO4 sulfate concentration (95% for sample I and 97% for sample II). In the Na-K-Mg triangle diagram, the fluid shows an immature water condition because the fluid has mixed with meteoric water. Based on the analysis of the geochemical data of the study area, it was shown that there is a connection with Ceunohot fault trending northeast to southwest as the controller of the flow of geothermal fluid.Keywords: Ternary triangle diagrams, geothermal fluid, chemical water compounds
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Gu, Shaohua, Yunqing Shi, and Zhangxin Chen. "Numerical Simulation of Fracture Permeability Change in Production of Pressure-sensitive Reservoirs with In-situ Stress Field." Open Petroleum Engineering Journal 8, no. 1 (October 22, 2015): 440–50. http://dx.doi.org/10.2174/1874834101508010440.
Full textAbstract:
In pressure sensitive reservoirs, interaction effects among the porous media flow field, the fracture field and the stress field can cause some specific flow characteristics entirely different from those in conventional reservoirs. Dynamic fracture behavior is one of them, which generates a change in the value of fracture aperture and even a variation in the anisotropy of permeability. In this paper, we focus on the dynamic behavior of fractures and some affecting factors, including driving pressure and in-situ stress. Numerical discrete fracture network (DFN) models are built and solved by the finite element method to investigate what the range-ability the fracture presents and what impact these affecting factors have. In these mathematical models, both dynamic fractures and the fluid-solid coupling are taken into account, and a stress-strain model, a flow field model and a fluid-solid coupling model are included. Based on the models, the variation of fracture aperture in pressure sensitive reservoirs is studied and the results show that a different direction and connectivity of fractures lead fracture dilation to varying degrees as pressure changes so that the idea of anisotropic fracture porosity is proposed for reservoir scale simulation. The study also indicates that the drop of formation pressure determines the conductivity of fractures and anisotropy of permeability but just has a slight impact on the direction of principal permeability. Finally, the study shows the interaction of the in-situ stress pressure and the fracture field.
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Singh, Jitendra Kumar, Gauri Shenkar Seth, and S. Ghousia Begum. "Unsteady MHD Natural Convective Flow of a Rotating Fluid over an Infinite Vertical Plate due to Oscillatory Movement of the Free-Stream with Hall and Ion-Slip Currents." Diffusion Foundations 11 (August 2017): 146–61. http://dx.doi.org/10.4028/www.scientific.net/df.11.146.
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In the present research study a mathematical analysis has been presented for unsteady MHD natural convective flow of a rotating fluid over an infinite vertical plate immersed in a fluid saturated porous medium with oscillating free-stream. The effects of Hall and ion-slip currents also considered on the fluid flow. The unsteady MHD flow over the vertical plate is induced due to thermal and concentration buoyancy forces and oscillatory movement of the free-stream. The partial differential equations governing the motion for the fluid flow are solved analytically. The effects of various pertinent flow parameters on the fluid velocity, fluid temperature and species concentration are presented in graphical form whereas that on skin friction and rate of heat and mass transfer at the plate are presented in tabular form. An interesting observation recorded from the present analysis that there appears reversal flow in the secondary flow direction due to presence of thermal and/or concentration buoyancy forces. However, in the absence of both reversals flow does not exist in the secondary flow direction. It is also noted that the thickness of momentum boundary layer decreases with rise in frequency of oscillations of the free-stream.
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Olabode, Oluwasanmi, Gerald Egeonu, Richard Afolabi, Charles Onuh, and Chude Okonji. "Computational Fluid Dynamics (CFD) for Modelling Multiphase Flow in Hilly-Terrain Pipelines." Diffusion Foundations 28 (December 2020): 33–55. http://dx.doi.org/10.4028/www.scientific.net/df.28.33.
Full textAbstract:
The design and operation of subsea pipelines over the life-cycle of an asset is vital for continuous oil and gas production. Qualitative design and effective production operation of pipelines depend on fluid type(s) involved in the flow; and in the case of multiphase flow, the need to understand the behaviour of the fluids becomes more imperative. This work presented in this report is borne out of the need for more accurate ways of predicting multiphase flow parameters in subsea pipelines with hilly-terrain profiles by better understanding their flow behaviors. To this end, Computational Fluid Dynamics has been used as against existing experimental and mechanistic methods which have inherent shortcomings. The results showed that multiphase flow parameters including flow-regimes, liquid hold-up and pressure drop in hilly-terrain pipelines can be modelled without associated errors in existing techniques. Similarity in trend was found when results of pressure gradient in downward-incline pipe were compared with results from existing correlations and mechanistic method. CFD can be used as a design tool and also a research tool into the understanding of the complexities of multiphase flow in hilly-terrain pipelines towards qualitative design and effective operation of hilly-terrain pipelines.
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Gao, Xiang, Tailu Li, Yao Zhang, Xiangfei Kong, and Nan Meng. "A Review of Simulation Models of Heat Extraction for a Geothermal Reservoir in an Enhanced Geothermal System." Energies 15, no. 19 (September 28, 2022): 7148. http://dx.doi.org/10.3390/en15197148.
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This paper reviews the heat transfer model for geothermal reservoirs, the fracture network in reservoirs, and the numerical model of hydraulic fracturing. The first section reviews the heat transfer models, which contain the single-porosity model, the dual-porosity model, and the multi-porosity model; meanwhile the mathematical equations of the porosity model are summarized. Then, this paper introduces the fracture network model in reservoirs and the numerical method of computational heat transfer. In the second section, on the basis of the conventional fracture theory, the PKN (Perkins–Kern–Nordgren) model and KGD (Khristianovic–Geertsma–De Klerk) model are reviewed. Meanwhile, the DFN (discrete fracture network) model, P3D (pseudo-3D) model, and PL3D (planar 3D) model are reviewed. The results show that the stimulated reservoir volume method has advantages in describing the fracture network. However, stimulated reservoir volume methods need more computational resources than conventional fracture methods. The third section reviews the numerical models of hydraulic fracturing, which contains the finite element method (FEM), the discrete element method (DEM), and the boundary element method (BEM). The comparison of these methods shows that the FEM can reduce the computational resources when calculating the fluid flow, heat transfer and fracture propagations in a reservoir. Thus, a mature model for geothermal reservoirs can be developed by coupling the processes of heat transfer, fluid flow and fracture propagation.
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Santosh, H. B., Mahesha, Chakravarthula S. K. Raju, and Oluwole Daniel Makinde. "The Flow of Radiated Carreau Dusty Fluid over Exponentially Stretching Sheet with Partial Slip at the Wall." Diffusion Foundations 16 (June 2018): 96–108. http://dx.doi.org/10.4028/www.scientific.net/df.16.96.
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In this study, we addressed the impact of magnetic field on fluid flow and heat transfer of an in compressible Carreau fluid over exponentially stretching sheet in addition with fluid and dust particle suspension. Thermal radiation and non-uniform heat source/sink were included to develop heat transport phenomena. Dusty fluids have various applications such as processing of material, nuclear heat treatment, cooling process, treatment of waste water etc. The relevant governing equations are converted into ordinary differential equation using similarity transformation the transformed ordinary differential equations are then solved numerically by shooting technique along with Runge-Kutta method The effect of certain parameters on the dimensionless velocity and temperature are presented graphically. The physical quantities of the flow such as the friction factor and Local Nusselt number were calculated. It was found from the study that the velocity slip parameter increases the temperature profiles.
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Massaro, Luigi, Amerigo Corradetti, Francesco d’Assisi Tramparulo, Stefano Vitale, Ernesto Paolo Prinzi, Alessandro Iannace, Mariano Parente, Chiara Invernizzi, Davoud Morsalnejad, and Stefano Mazzoli. "Discrete Fracture Network Modelling in Triassic–Jurassic Carbonates of NW Lurestan, Zagros Fold-and-Thrust Belt, Iran." Geosciences 9, no. 12 (November 26, 2019): 496. http://dx.doi.org/10.3390/geosciences9120496.
Full textAbstract:
In this study, discrete fracture network (DFN) modelling was performed for Triassic–Jurassic analogue reservoir units of the NW Lurestan region, Iran. The modelling was elaborated following a multi-scale statistical sampling of the fracture systems characterising the analysed succession. The multi-scale approach was performed at two different observation scales. At the macro-scale, a digital outcrop analysis was carried out by means of a digital line-drawing based on camera-acquired images, focussing on the distribution of major throughgoing fractures; at the meso-scale, the scan line method was applied to investigate the background fractures of the examined formations. The gathered data were statistically analysed in order to estimate the laws governing the statistical distribution of some key fracture set attributes, namely, spacing, aperture, and height. The collected dataset was used for the DFN modelling, allowing the evaluation of the relative connectivity of the fracture systems and, therefore, defining the architecture and the geometries within the fracture network. The performed fracture modelling, confirmed, once again, the crucial impact that large-scale throughgoing fractures have on the decompartmentalization of a reservoir and on the related fluid flow migration processes. The derived petrophysical properties distribution showed in the models, defined the Kurra Chine Fm. and, especially, the Sehkaniyan Fm. as good-quality reservoir units, whereas the Sarki Fm was considered a poor-quality reservoir unit.
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Kottwitz, Maximilian O., Anton A. Popov, Steffen Abe, and Boris J. P. Kaus. "Investigating the effects of intersection flow localization in equivalent-continuum-based upscaling of flow in discrete fracture networks." Solid Earth 12, no. 10 (October 5, 2021): 2235–54. http://dx.doi.org/10.5194/se-12-2235-2021.
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Abstract. Predicting effective permeabilities of fractured rock masses is a crucial component of reservoir modeling. Its often realized with the discrete fracture network (DFN) method, whereby single-phase incompressible fluid flow is modeled in discrete representations of individual fractures in a network. Depending on the overall number of fractures, this can result in high computational costs. Equivalent continuum models (ECMs) provide an alternative approach by subdividing the fracture network into a grid of continuous medium cells, over which hydraulic properties are averaged for fluid flow simulations. While continuum methods have the advantage of lower computational costs and the possibility of including matrix properties, choosing the right cell size to discretize the fracture network into an ECM is crucial to provide accurate flow results and conserve anisotropic flow properties. Whereas several techniques exist to map a fracture network onto a grid of continuum cells, the complexity related to flow in fracture intersections is often ignored. Here, numerical simulations of Stokes flow in simple fracture intersections are utilized to analyze their effect on permeability. It is demonstrated that intersection lineaments oriented parallel to the principal direction of flow increase permeability in a process we term intersection flow localization (IFL). We propose a new method to generate ECMs that includes this effect with a directional pipe flow parameterization: the fracture-and-pipe model. Our approach is compared against an ECM method that does not take IFL into account by performing ECM-based upscaling with a massively parallelized Darcy flow solver capable of representing permeability anisotropy for individual grid cells. While IFL results in an increase in permeability at the local scale of the ECM cell (fracture scale), its effects on network-scale flow are minor. We investigated the effects of IFL for test cases with orthogonal fracture formations for various scales, fracture lengths, hydraulic apertures, and fracture densities. Only for global fracture porosities above 30 % does IFL start to increase the systems permeability. For lower fracture densities, the effects of IFL are smeared out in the upscaling process. However, we noticed a strong dependency of ECM-based upscaling on its grid resolution. Resolution tests suggests that, as long as the cell size is smaller than the minimal fracture length and larger than the maximal hydraulic aperture of the considered fracture network, the resulting effective permeabilities and anisotropies are resolution-independent. Within that range, ECMs are applicable to upscale flow in fracture networks.
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Kottwitz, Maximilian O., Anton A. Popov, Steffen Abe, and Boris J. P. Kaus. "Investigating the effects of intersection flow localization in equivalent-continuum-based upscaling of flow in discrete fracture networks." Solid Earth 12, no. 10 (October 5, 2021): 2235–54. http://dx.doi.org/10.5194/se-12-2235-2021.
Full textAbstract:
Abstract. Predicting effective permeabilities of fractured rock masses is a crucial component of reservoir modeling. Its often realized with the discrete fracture network (DFN) method, whereby single-phase incompressible fluid flow is modeled in discrete representations of individual fractures in a network. Depending on the overall number of fractures, this can result in high computational costs. Equivalent continuum models (ECMs) provide an alternative approach by subdividing the fracture network into a grid of continuous medium cells, over which hydraulic properties are averaged for fluid flow simulations. While continuum methods have the advantage of lower computational costs and the possibility of including matrix properties, choosing the right cell size to discretize the fracture network into an ECM is crucial to provide accurate flow results and conserve anisotropic flow properties. Whereas several techniques exist to map a fracture network onto a grid of continuum cells, the complexity related to flow in fracture intersections is often ignored. Here, numerical simulations of Stokes flow in simple fracture intersections are utilized to analyze their effect on permeability. It is demonstrated that intersection lineaments oriented parallel to the principal direction of flow increase permeability in a process we term intersection flow localization (IFL). We propose a new method to generate ECMs that includes this effect with a directional pipe flow parameterization: the fracture-and-pipe model. Our approach is compared against an ECM method that does not take IFL into account by performing ECM-based upscaling with a massively parallelized Darcy flow solver capable of representing permeability anisotropy for individual grid cells. While IFL results in an increase in permeability at the local scale of the ECM cell (fracture scale), its effects on network-scale flow are minor. We investigated the effects of IFL for test cases with orthogonal fracture formations for various scales, fracture lengths, hydraulic apertures, and fracture densities. Only for global fracture porosities above 30 % does IFL start to increase the systems permeability. For lower fracture densities, the effects of IFL are smeared out in the upscaling process. However, we noticed a strong dependency of ECM-based upscaling on its grid resolution. Resolution tests suggests that, as long as the cell size is smaller than the minimal fracture length and larger than the maximal hydraulic aperture of the considered fracture network, the resulting effective permeabilities and anisotropies are resolution-independent. Within that range, ECMs are applicable to upscale flow in fracture networks.
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Kusumastuti, Dwi Listriana. "Penerapan Dinamika Fluida dalam Perhitungan Kecepatan Aliran dan Perolehan Minyak di Reservoir." ComTech: Computer, Mathematics and Engineering Applications 5, no. 2 (December 1, 2014): 707. http://dx.doi.org/10.21512/comtech.v5i2.2232.
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Water, oil and gas inside the earth are stored in the pores of the reservoir rock. In the world of petroleum industry, calculation of volume of the oil that can be recovered from the reservoir is something important to do. This calculation involves the calculation of the velocity of fluid flow by utilizing the principles and formulas provided by the Fluid Dynamics. The formula is usually applied to the fluid flow passing through a well defined control volume, for example: cylinder, curved pipe, straight pipes with different diameters at the input and output, and so forth. However, because of reservoir rock, as the fluid flow medium, has a wide variety of possible forms of the control volumes, hence, calculation of the velocity of the fluid flow is becoming difficult as it would involve calculations of fluid flow velocity for each control volume. This difficulties is mainly caused by the fact that these control volumes, that existed in the rock, cannot be well defined. This paper will describe a method for calculating this fluid flow velocity of the control volume, which consists of a combination of laboratory measurements and the use of some theories in the Fluid Dynamics. This method has been proofed can be used for calculating fluid flow velocity as well as oil recovery in reservoir rocks, with fairly good accuration.
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Gaißer, H. "Fluiddynamik in der Cigarette und deren Einfluß auf den Zugwiderstand." Beiträge zur Tabakforschung International/Contributions to Tobacco Research 16, no. 1 (May 1, 1994): 11–46. http://dx.doi.org/10.2478/cttr-2013-0630.
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AbstractThe objective of the theoretical study is to present a model that simulates the instationary flow characteristics within cigarettes which are adjusted to a routine smoking machine. By assuming laminar fluid flow the well knownKozeny-Carman equation is used to evaluate the flow impedance of cigarettes. The model parameters are determined by five variations of routine pressure-drop measurements yielding the entire set of flow impedances, which are necessary for describing a steady state Fluid-Network. Using this relation further elements of the fluid dynamics, e.g. the Fluid-Inductor, a storage element of kinetic energy (fluid inertor), and the Fluid-Capacitor, a storage element of potential energy (fluid volume), are evaluated. In addition, the electrical and fluid dynamical analogies are demonstrated. The model uses a set of distributed parameters including pneumatic impedances, capacitors and inductors, to represent filtered cigarettes and a second order linear partial differential equation to describe the fluid flow within the cigarettes. A simple presentation of the Fluid-Network with lumped parameters is analysed and its significant time constants are determined. A characteristical value for the time constant of the cigarette fluid-inertor is given by TL ≈ 0.02 ms and depending on the fluid volume of cigarette their dominant time parameter is given by TC ≈ 2 ms. Finally the transient fluid flow within cigarettes in a conventional smoking machine is considered including a simulation of their fluid dynamics. A simple estimation gives the time response of the system (consisting of cigarettes and routine smoking machine) with TcR ≈ 70 ms as a product of dead and sweep volume times the pressure drop of unencapsulated cigarettes. Variation of parameters caused by cigarette pressure drops and dead volumes of the smoking machine are simulated and discussed.
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Polii, Jeferson. "Pemodelan Penurunan Tekanan Brine di Dalam Pipa Injeksi pada Lapangan Panas Bumi Dieng." Jurnal MIPA 6, no. 2 (October 2, 2017): 32. http://dx.doi.org/10.35799/jm.6.2.2017.17332.
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Injeksi brine hasil dari fluida produksi panas bumi digunakan untuk mengisi volume pori batuan reservoir, mencegah penurunan tekanan batuan yang terlalu cepat, dan mencegah polusi panas dan polusi kimia pada lingkungan yang disebabkan oleh kandungan kimia tertentu pada brine. Pada pipa aliran brine terjadi penurunan tekanan fluida sepanjang aliran. Di lapangan panas bumi Dieng, konsentrasi silika sangat tinggi, sehingga penurunan temperatur saturasi memicu desposisi silika. Penurunan tekanan sepanjang pipa aliran brine dari pompa Vertikal Atas (VA) 7 ke pond di pad 29 di lapangan panas bumi Dieng akan menyebabkan penurunan temperatur saturasi, selain juga kehilangan panas secara alami. Perhitungan penurunan tekanan fluida brine berdasarkan perhitungan Harrison-Freeston dan metode dari Zhao, yang dikembangkan dengan algoritma menggunakan Macro Excel. Sehingga dengan memodelkan penurunan tekanan sepanjang pipa alir, dapat dikembangkan untuk perhitungan penurunan temperatur dan pengendapan silika di pipa aliran brine untuk injeksi panas bumi.Brine injection from geothermal production fluids is used to fill reservoir pore rock volumes, preventing rapid rock pressure drops, and preventing heat pollution and chemical pollution in the environment caused by certain chemical constituents in the brine. Decrease fluid pressure along the flow on the brine flow pipe. In the Dieng geothermal field, the silica concentration is very high, so the decrease in saturation temperature triggers the silica desposition. The pressure drop along the brine flow pipe from the Upper Vertical (VA) 7 pump to the pond in pad 29 in Dieng geothermal field will cause a decrease in saturation temperature, as well as natural heat loss. The calculation of the decrease in brine fluid pressure based on Harrison-Freeston calculations and methods of Zhao, developed with algorithms using Macro Excel. By modeling the pressure drop along the flow line, it can be developed for the calculation of temperature drop and deposition of silica in the brine flow pipe for geothermal injection
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Laidoudi, Houssem, and Oluwole Daniel Makinde. "Mixed Convection Heat Transfer around a Tandem Circular Cylinders in Incompressible Downward Flow." Diffusion Foundations 16 (June 2018): 12–20. http://dx.doi.org/10.4028/www.scientific.net/df.16.12.
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In this paper, we numerically examine the mixed convective flow around a confined tandem heated circular cylinders embedded in a vertical channel in order to determine exactly the effects of opposing thermal buoyancy and distance between cylinders (S) on the behavior of fluid flow and heat transfer rate. The dimensionless governing equations involving momentum, continuity and energy are obtained and solved in a steady laminar flow regime for the conditions:Re= 5 to 40 andS= 0 to 5d, at fixed values of Prandtl numberPr= 1, Richardson numberRi= 1 and blockage ratioβ= 1/5. The fluid flow and temperature field are illustrated in terms of streamline and isotherm contours. The average Nusselt number is also computed to quantify the effect of fluid flow and heat transfer characteristics on amount of heat transfer rate.
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Takwim, R. N. Akhsanu, and Kris Witono. "ANALISIS UNJUK KERJA VENTURI VAKUM DENGAN VARIASI DIMENSI DAN VISKOSITAS FLUIDA." INFO-TEKNIK 19, no. 1 (July 25, 2018): 55. http://dx.doi.org/10.20527/infotek.v19i1.5142.
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In the venturi vacuum, to produce a vacuum condition, a liquid fluid flow is
required which is driven by a centrifugal pump through the venturi passage. The
amount of vacuum pressure generated by venturi is influenced by the increase of flow
velocity due to the diminution of the cross-section which follow Bernoulli principle.
The flow velocity on the channel is influenced by the discharge generated by the
pump following the continuity law. In addition to speed, channel input pressure is
also a variable that affects venturi vacuum pressure. Performance of a setrifugal pump
in the form of flow and pressure discharge greatly affect venturi vacuum
performance, so that the variables affecting the performance of a setrifugal pump
such as fluid viscosity, will also affect the venturi vacuum performance.
Therefore, it is necessary to evaluate the effect of viscosity and venturi dimension on
vacuum pressure and discharge into the main objective of this study so that the
variables can improve the venturi vacuum pump performance.
In this study liquid fluid with three variations of viscosity flowed through three
different venturi dimension variations. Then measured parameters that occur, such as
fluid flow fluid flow, fluid pressure fluid and vacuum pressure that occurs in the tube.
From this study obtained, at the angle of diffuser 5o the lowest vacuum pressure of -
66.75 cmHg occurs in water fluid with viscosity of 17 centipoise. Similarly, at the
angle of the diffuser 6.5o the value of the lowest vacuum pressure is also produced by
a water fluid of -68 cmHg which is the lowest value compared to other diffuser angles
and other fluid viscosities. While at 8o diffuser angle, the lowest vacuum pressure
value is also produced by water fluid of -64.5 cmHg.
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Armandine Les Landes, Antoine, Théophile Guillon, Mariane Peter-Borie, Arnold Blaisonneau, Xavier Rachez, and Sylvie Gentier. "Locating Geothermal Resources: Insights from 3D Stress and Flow Models at the Upper Rhine Graben Scale." Geofluids 2019 (May 12, 2019): 1–24. http://dx.doi.org/10.1155/2019/8494539.
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To be exploited, geothermal resources require heat, fluid, and permeability. These favourable geothermal conditions are strongly linked to the specific geodynamic context and the main physical transport processes, notably stresses and fluid circulations, which impact heat-driving processes. The physical conditions favouring the setup of geothermal resources can be searched for in predictive models, thus giving estimates on the so-called “favourable areas.” Numerical models could allow an integrated evaluation of the physical processes with adapted time and space scales and considering 3D effects. Supported by geological, geophysical, and geochemical exploration methods, they constitute a useful tool to shed light on the dynamic context of the geothermal resource setup and may provide answers to the challenging task of geothermal exploration. The Upper Rhine Graben (URG) is a data-rich geothermal system where deep fluid circulations occurring in the regional fault network are the probable origin of local thermal anomalies. Here, we present a current overview of our team’s efforts to integrate the impacts of the key physics as well as key factors controlling the geothermal anomalies in a fault-controlled geological setting in 3D physically consistent models at the regional scale. The study relies on the building of the first 3D numerical flow (using the discrete-continuum method) and mechanical models (using the distinct element method) at the URG scale. First, the key role of the regional fault network is taken into account using a discrete numerical approach. The geometry building is focused on the conceptualization of the 3D fault zone network based on structural interpretation and generic geological concepts and is consistent with the geological knowledge. This DFN (discrete fracture network) model is declined in two separate models (3D flow and stress) at the URG scale. Then, based on the main characteristics of the geothermal anomalies and the link with the physics considered, criteria are identified that enable the elaboration of indicators to use the results of the simulation and identify geothermally favourable areas. Then, considering the strong link between the stress, fluid flow, and geothermal resources, a cross-analysis of the results is realized to delineate favourable areas for geothermal resources. The results are compared with the existing thermal data at the URG scale and compared with knowledge gained through numerous studies. The good agreement between the delineated favourable areas and the locations of local thermal anomalies (especially the main one close to Soultz-sous-Forêts) demonstrates the key role of the regional fault network as well as stress and fluid flow on the setup of geothermal resources. Moreover, the very encouraging results underline the potential of the first 3D flow and 3D stress models at the URG scale to locate geothermal resources and offer new research opportunities.
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Arman, Rizky, Yovial Mahyoedin, Kaidir Kaidir, and Nando Desilpa. "STUDI ALIRAN AIR PADA BALL VALVE DAN BUTTERFLY VALVE MENGGUNAKAN METODE SIMULASI COMPUTATIONAL FLUID DYNAMICS." JURNAL KAJIAN TEKNIK MESIN 4, no. 1 (May 22, 2019): 38–49. http://dx.doi.org/10.52447/jktm.v4i1.1474.
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ABSTRAKValve adalah alat mekanis yang mengatur aliran atau tekanan cairan. Fungsinya adalah menutup atau membuka aliran, mengontrol laju aliran, mengalihkan aliran, mencegah aliran balik, mengontrol tekanan, atau mengurangi tekanan. Masalah yang umumnya ditemui adalah penutupan valve tidak sempurna dikarenakan adanya kotoran-kotoran yang menghalangi penutupnya untuk menutup secara sempurna. Penanganannya yang paling sederhana yaitu membersihkan dudukan dari kotoran-kotoran tadi secara intensif dan dilakukan pelumasan. Penelitian ini bertujuan untuk menjelaskan gambaran tentang simulasi aliran pada ball valve dan butterfly valve. Dan menjelaskan perbandingan tekanan, temperatur dan kecepatan distribusi air pada dua jenis valve. Tekanan fluida pada kondisi tertutup berbeda dengan kondisi terbuka. Hal ini akan berdampak terhadap kekuatan ball valve dan butterfly valve. Tekanan yang besar atau melebihi spesifikasi akan mempengaruhi mekanisme kerja dan kekuatan material. Pengaruh tekanan ini menjadi sangat penting dalam ball valve dan butterfly valve karena tekanan fluida dengan temperatur, pada kondisi tertentu bisa di luar batas spesifikasi khususnya pada ball valve Sanitary SS316 Mounting Pad 3 inci dan butterfly valve Sanitary SS 304 3 inci. Metode yang digunakan adalah Computational Fluid Dynamics dengan bantuan Software Flow Simulasi Solidwork 2014.Kata Kunci: Ball and Butterfly Valve, Solidwork, Flow Simulasi, CFD, Tekanan, Temperatur, Kecepatan aliran. ABSTRACTValves are mechanical devices that regulate fluid flow or pressure. Its function can close or open the flow, control the flow rate, divert flow, prevent backflow, control pressure, or reduce pressure. The problem commonly encountered is that the valve closure is not perfect due to the impurities that prevent the cover from closing completely. The simplest handling is to clean the holder from the dirts earlier and do lubrication. This study aims to explain the description of the flow simulation on ball valve and butterfly valve. This study also explain the comparison of pressure, temperature and velocity of water distribution in two types of valve heads. Fluid pressure under closed conditions is different from opening conditions. This will affect the strength of the ball valve and butterfly valve as a valve. Pressure that is large or exceeds specifications will affect the working mechanism and material strength. The effect of this pressure becomes very important in the ball valve and butterfly valve because of fluid pressure with temperature under certain conditions it can be out of the specification limits, especially in Sanitary SS316 Mounting Pad 3-inch ball valve and SS 304 3 inch Sanitary butterfly valve. This method was used in research is Computational Fluid Dynamics by utilizing of Flow Simulation Solidwork 2014 Software.Keywords: Ball Valve, Butterfly Valve, Solidwork 2014, Flow Simulation, CFD, Pressure, Temperature, Velocity
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Mifta Aroyyani, Agus Nuramal, and Hendri Hestiawan. "SIMULASI ANALISIS VELOCITY ALIRAN FLUIDA PADA TANGKI REAKTOR NUKLIR MENGGUNAKAN METODE COMPUTATIONAL FLUID DYNAMICS (CFD)." Rekayasa Mekanika 6, no. 2 (October 4, 2022): 83–88. http://dx.doi.org/10.33369/rekayasamekanika.v6i2.25461.
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Center for Applied Nuclear Science and Technology (Pusat Sains dan Teknologi Nuklir Terapan /PSTNT) is a work unit that is under and directly responsible to the Deputy for Nuclear Science and Applications of Nuclear Technology, National Nuclear Energy Agency. In PSTNT Bandung, the function of the tank is as a container to place the reactor components, the reactor shield for the heat exchanger and as a place for nuclear reactions to take place. In nuclear reactor tank flow distribution ocures in various velocity.The purpose of this practical work is to analyze the velocity of fluid flow in the reactor tank from the inlet flow to the bottom surface of the reactor and from the bottom surface to the top surface of the TRIGA 2000 reactor. The method used in this practical work is the Computational Fluid Dynamics (CFD) Velocity method. CFD is a method for simulating fluid flow. The method is processed numerically and then digitally modeled. In practice, the authors modeled and studied the conceptual design of the reactor system using CFD based on Gambit and Fluent applications in a reactor tank. GAMBIT is an application produced by fluent inc. which is useful for making a model and discrete (meshing) to be analyzed by numerical methods. Fluent is an application that can solve fluid flow cases with the results obtained after discretizing the GAMBIT application. The results by CFD shows the distribution of fluid flow from the inlet pipe to the bottom surface of the reactor tank then the flow rises to the top surface to the outlet pipe. The velocity of the fluid flow from the inlet flow to the bottom surface was getting smaller, and the smallest value was at the bottom of the nuclear reactor, by 0.164 m/s and the flow distribution from the bottom surface to the top surface of the velocity value in a nuclear reactor would be bigger by the largest value being on the top surface of the nuclear reactor is 2.9 m/s.
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Riandika, Putu, Nyoman Arya Wigraha, and I. Nyoman Pasek Nugraha. "PENGARUH KECEPATAN ALIRAN FLUIDA TERHADAP CAPAIAN SUHU OPTIMAL HASIL RANCANGAN COOLBOX ZERO POLLUTION." Jurnal Pendidikan Teknik Mesin Undiksha 6, no. 3 (November 1, 2018): 160. http://dx.doi.org/10.23887/jjtm.v6i3.14989.
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Pemanfaatan teknologi telah merambah dalam semua aspek kehidupan manusia, salah satunya teknologi pada bidang peralatan rumah tangga . Household appliances adalah salah satu contoh teknologi yang terus berkembang mengikuti kebutuhan manusia akan berbagai factor seperti, kemudahan, keandalan kenyamanan, ekonomi, dan sebagainya. Ini terlihat pada penjualan lemari es yang terus meningkat ditiap tahunnya. Namun perkembangan mesin pendingin masih belum sempurna karena masih terdapat kekurangan dilihat dari digunakannya bahan kimia yang kurang ramah lingkungan seperti Freon. Maka dari itu penulis berkeinginan untuk merancang dan meneliti Coolbox Zero Pollution yang tidak menggunakan Freon. Penelitian ini bertujuan untuk mengoptimalkan unjuk kerja dari Coolbox Zero Pollution dan mengetahui pengaruh kecepatan aliran fluida terhadap suhu yang dicapai Coolbox Zero Pollution. Dari hasil penelitian didapatkan penggunaan kecepatan aliran 0,033 m/s perbandingan suhu fluida radiator coolant, air + radiator coolant, dan air adalah 12,180C : 12,450C : 13,420C. Pada penggunaan kecepatan aliran 0,049 m/s perbandingan suhu fluida radiator coolant, air + radiator coolant, dan air adalah 11,630C : 12,110C : 13,060C. Pada penggunaan kecepatan aliran 0,071 m/s perbandingan suhu fluida radiator coolant, air + radiator coolant, dan air adalah 11,170C : 11,620C : 12,470C.Kata Kunci : coolbox, peltier, pompa, fluida, suhu, pendingin Utilization of technology has penetrated in all aspects of human life, one of them technology in the field of household appliances. Household appliances is one example of technology that continues to grow following human needs for various factors such as convenience, comfort, economy, reliability, and so on. This is seen in the sales of refrigerators that continue to increase each year. However, the development of the cooling machine is still not perfect because there are still deficiencies seen from the use of less environmentally friendly chemicals such as Freon. Therefore the author intends to design and examine Coolbox Zero Pollution which does not use Freon. This study aims to optimize the performance of Coolbox Zero Pollution and to know the effect of fluid flow velocity on temperature reached by Coolbox Zero Pollution. From the result of the research, the use of flow velocity of 0.033 m / s temperature ratio of fluid radiator coolant, water + radiator coolant, and water is 12,180C: 12,450C: 13,420C. At a flow rate of 0.049 m / s the temperature ratio of the fluid radiator coolant, water + radiator coolant, and water is 11.630C: 12.110C: 13.060C. At a flow rate of 0.071 m / s the temperature ratio of the fluid radiator coolant, water + radiator coolant, and water is 11,170C: 11,620C: 12,470Ckeyword : coolbox, peltier, pump, fluid, temperature, cooler
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McClure, Mark, and Roland Horne. "Characterizing Hydraulic Fracturing With a Tendency-for-Shear-Stimulation Test." SPE Reservoir Evaluation & Engineering 17, no. 02 (February 20, 2014): 233–43. http://dx.doi.org/10.2118/166332-pa.
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Summary The classical concept of hydraulic fracturing is that a single, planar, opening mode fracture propagates through the formation. In recent years, there has been a growing consensus that natural fractures play an important role during stimulation in many settings. There is not universal agreement on the mechanisms by which natural fractures affect stimulation, and these mechanisms may vary depending on formation properties. One potentially important mechanism is shear stimulation, in which increased fluid pressure induces slip and permeability enhancement on pre-existing fractures. We propose a tendency-for-shear-stimulation (TSS) test as a direct, relatively unambiguous method for determining the degree to which shear stimulation contributes to stimulation in a formation. In a TSS test, fluid injection is performed while maintaining the bottomhole fluid pressure slightly less than the minimum principal stress. Under these conditions, shear stimulation is the only possible mechanism for permeability enhancement (except, perhaps, thermally induced tensile fracturing). A TSS test is different from a conventional procedure because injection is performed at a specified pressure (rather than a specified rate). With injection at a specified rate, fluid pressure may exceed the minimum principal stress, and it may cause tensile fractures to propagate through the formation. If this occurs, it will be ambiguous whether stimulation was because of shear stimulation or tensile fracturing. Maintaining pressure less than the minimum principal stress ensures that the effect of shear stimulation can be isolated. Low-rate injectivity tests could be performed before and after the TSS test to estimate formation permeability. An increase in formation permeability would indicate that shear stimulation has occurred. The flow-rate transient during injection may also be interpreted to identify shear stimulation. Numerical simulations of shear stimulation were performed with a discrete-fracture-network (DFN) simulator that couples fluid flow with the stresses induced by fracture deformation. These simulations were used to qualitatively investigate how shear stimulation and fracture connectivity affect the results of a TSS test. Two specific field projects are discussed as examples of a TSS test, the Enhanced Geothermal Systems (EGS) projects at Desert Peak, Nevada, and Soultz-sous-Forêts, France.
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Mahmoodpour, Saeed, Mrityunjay Singh, Christian Obaje, Sri Kalyan Tangirala, John Reinecker, Kristian Bär, and Ingo Sass. "Hydrothermal Numerical Simulation of Injection Operations at United Downs, Cornwall, UK." Geosciences 12, no. 8 (July 29, 2022): 296. http://dx.doi.org/10.3390/geosciences12080296.
Full textAbstract:
The United Downs Deep Geothermal Project (UDDGP) is designed to utilize a presumably permeable steep dipping fault damage zone (constituting the hydrothermal reservoir in a very low permeability granitic host rock) for fluid circulation and heat extraction between an injection well at 2.2 km depth (UD−2) and a production well at 5 km depth (UD−1). Soft hydraulic stimulation was performed to increase the permeability of the reservoir. Numerical simulations are performed to analyze the hydraulic stimulation results and evaluate the increase in permeability of the reservoir. Experimental and field data are used to characterize the initial reservoir static model. The reservoir is highly fractured, and two distinct fracture networks constitute the equivalent porous matrix and fault zone, respectively. Based on experimental and field data, stochastic discrete fracture networks (DFN) are developed to mimic the reservoir permeability behavior. Due to the large number of fractures involved in the stochastic model, equivalent permeability fields are calculated to create a model which is computationally feasible. Hydraulic test and stimulation data from UD−1 are used to modify the equivalent permeability field based on the observed difference between the real fractured reservoir and the stochastic DFN model. Additional hydraulic test and stimulation data from UD−2 are used to validate this modified permeability. Results reveal that the equivalent permeability field model derived from observations made in UD−1 is a good representation of the actual overall reservoir permeability, and it is useful for future studies. The numerical simulation results show the amount of permeability changes due to the soft hydraulic stimulation operation. Based on the validated permeability field, different flow rate scenarios of the petrothermal doublet and their respective pressure evolution are examined. Higher flow rates have a strong impact on the pressure evolution. Simulations are performed in the acidized enhanced permeability region to make a connection between the ongoing laboratory works on the acid injection and field response to the possible acidizing stimulation.
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Jasmita, Murda, and Ardian Putra. "Identifikasi Karakteristik Mata Air Panas Bumi di Sibanggor Tonga Kabupaten Mandailing Natal Menggunakan Diagram Segitiga Fluida." Jurnal Fisika Unand 9, no. 4 (January 25, 2021): 428–35. http://dx.doi.org/10.25077/jfu.9.4.428-435.2020.
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Telah dilakukan penelitian tentang identifikasi karakteristik fluida mata air panas tipe fluida, kesetimbangan, asal usul sumber fluida dan pengenceran mata air panas bumi di Sibanggor Tonga Kabupaten Mandailing Natal. Sampel penelitian diambil dari lima sumber mata air dengan volume sampel di setiap lokasi sebanyak 500 ml. Nilai pH dari 5 titik mata air panas berkisar dari 0,6 sampai 6,3 dan pengukuran temperatur permukaan diperoleh mulai dari 37,6 oC hingga 95,3 oC. Konsentrasi unsur Na, K, Mg, K, B dan Li diukur menggunakan Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES). Pengukuran konsentrasi unsur Cl diperoleh dari persamaan konduktivitas yang didapatkan dari alat conductivity meter dan pengukuran konsentrasi SO4 dengan metode visible spectroscopy. Pengukuran konsentrasi HCO3 diukur dengan metode titrasi asam basa. Diagram Cl-HCO3-SO4 menunjukkan semua fluida bertipe sulfat-klorida dan diagram Na-K-Mg menunjukkan semua fluida berada pada immature water yang mengindikasikan fluida telah mengalami reaksi dengan unsur lain saat menuju permukaan. Asal sumber fluida berada jauh dari reservoir atau aliran fluida bergerak secara lateral saat menuju permukaan, yang terlihat dari diagram Cl-B-Li. Research has been carried out on the identification of the characteristics of the hot spring fluid type, equilibrium, the origin of the fluid source and the dilution of the geothermal springs in Sibanggor Tonga, Mandailing Natal Regency. The research sample was taken from five springs with a sample volume of 500 ml at each location. The pH values of the 5 hot springs ranged from 0.6 to 6.3 and surface temperature measurements were obtained from 37.6°C to 95.3°C. The concentrations of Na, K, Mg, K, B and Li were measured using Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES). Measurement of the element concentration of Cl is obtained from the conductivity equation obtained from a conductivity meter and measurement of SO4 concentrations using the visible spectroscopy method. HCO3 concentration measurements were measured by the acid-base titration method. The Cl-HCO3-SO4 diagram shows all sulfate-chloride type fluids and the Na-K-Mg diagram shows all fluids are in immature water which indicates that the fluid has undergone a reaction with other elements when it reaches the surface. As long as the fluid source is far from the reservoir or the fluid flow moves laterally towards the surface, as seen from the Cl-B-Li diagram.
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Nwaigwe, Chinedu, and Oluwole Daniel Makinde. "Finite Difference Investigation of a Polluted Non-Isothermal Variable-Viscosity Porous Media Flow." Diffusion Foundations 26 (March 2020): 145–56. http://dx.doi.org/10.4028/www.scientific.net/df.26.145.
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We extend previous studies of channel flows to porous media flows with combined effects ofboth heat and mass transfer. We consider a temperaturedependent viscosity fluid and a concentrationdependent diffusivity in an unsteady and pressuredriven nonisothermal Brinkman flow. This leads to the governing equations for velocity, concentration and temperature. By lagging nonlinear coefficients, in time, a convergent finite difference scheme is formulated. We adopt the method of manufactured solutions to verify the convergence and second order spatial accuracy of the scheme. The impact of the flow parameters on the flow fields are numerically investigated. The results show that increase in the Darcy number and temperature parameter both increase the velocity while the increase in the pollutant diffusion parameter decreases the pollutant concentration.
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Kiuru, Risto, Dorka Király, Gergely Dabi, and Lars Jacobsson. "Comparison of DFN Modelled Microfracture Systems with Petrophysical Data in Excavation Damaged Zone." Applied Sciences 11, no. 7 (March 24, 2021): 2899. http://dx.doi.org/10.3390/app11072899.
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Physical and petrographic properties of drill core specimens were determined as a part of investigations into excavation damage in the dedicated study area in the ONKALO® research facility in Olkiluoto, Western Finland. Microfractures in 16 specimens from two drillholes were analysed and used as a basis for fractal geometry-based discrete fracture network (DFN) modelling. It was concluded that the difference in resistivity between pegmatoid granite (PGR) and veined gneiss (VGN) specimens of similar porosity was likely due to differences in the types of microfractures. This hypothesis was confirmed from microfracture analysis and simulation: fractures in gneiss were short and mostly in one preferred orientation, whereas the fractures in granite were longer and had two preferred orientations. This may be due to microstructure differences of the rock types or could suggests that gneiss and granite may suffer different types of excavation damage. No dependencies on depth from the excavated surface were observed in the geometric parameters of the microfractures. This suggests that the excavation damaged zone cannot be identified based on the changes in the parameters of the microfracture networks, and that the disturbed layer observed by geophysical methods may be caused by macro-scale fractures.
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Bansal, Nency, Turki Aljrees, Dhirendra Prasad Yadav, Kamred Udham Singh, Ankit Kumar, Gyanendra Kumar Verma, and Teekam Singh. "Real-Time Advanced Computational Intelligence for Deep Fake Video Detection." Applied Sciences 13, no. 5 (February 27, 2023): 3095. http://dx.doi.org/10.3390/app13053095.
Full textAbstract:
As digitization is increasing, threats to our data are also increasing at a faster pace. Generating fake videos does not require any particular type of knowledge, hardware, memory, or any computational device; however, its detection is challenging. Several methods in the past have solved the issue, but computation costs are still high and a highly efficient model has yet to be developed. Therefore, we proposed a new model architecture known as DFN (Deep Fake Network), which has the basic blocks of mobNet, a linear stack of separable convolution, max-pooling layers with Swish as an activation function, and XGBoost as a classifier to detect deepfake videos. The proposed model is more accurate compared to Xception, Efficient Net, and other state-of-the-art models. The DFN performance was tested on a DFDC (Deep Fake Detection Challenge) dataset. The proposed method achieved an accuracy of 93.28% and a precision of 91.03% with this dataset. In addition, training and validation loss was 0.14 and 0.17, respectively. Furthermore, we have taken care of all types of facial manipulations, making the model more robust, generalized, and lightweight, with the ability to detect all types of facial manipulations in videos.
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Gunawan, Aji. "RANCANG BANGUN MINI LAB FLUIDA SEBAGAI OBJEK PENGAMBILAN DATA UNTUK KEPERLUAN PENELITIAN DI UNIVERSITAS MERCUBUANA KERANGGAN." Jurnal Teknik Mesin 8, no. 2 (March 13, 2020): 48. http://dx.doi.org/10.22441/jtm.v8i2.4535.
Full textAbstract:
Abstrak
Lab fluida difungsikan sebagai tempat pengambilan data untuk proses pembelajaran maupun penelitian tentang fluida. Kondisi saat ini belum adanya lab fluida di universitas mercubuana keranggan yang digunakan sebagai objek pengambilan data untuk penelitian. Rancang bangun mini lab fluida dibutuhkan untuk menunjang kegiatan pengambilan data. Studi literatur untuk perancangan menggunakan buku, jurnal, dan internet. Diskusi dilakukan dengan dosen pembimbing dan mahasiswa yang akan melakukan penelitian pada mini lab fluida.Berdasarkan perhitungan beban, meja menggunakan besi hollow 60x40x4. Pompa yang digunakan adalah pompa sentrifugal dengan debit 9 m3/h dan total head 5 m. Pipa yang digunakan adalah pipa galvanis 1 1/2 inch. Valve dengan type ball valve, dan tangki dengan kapasitas 300 L. Pengaturan speed pompa menggunakan VSD (Variabel Speed Drive) dan untuk mengatur voltage menggunakan AVR (Analog Voltage Regulator).
Kata kunci : Lab fluida, perpipaan, pengujian
Abstract
The fluid lab is functioned as a place for retrieving data in order to learn the process and leading research of fluid. At this time, the fluid lab is not yet available in Mercubuana University Kranggan, which is necessary utilized for research. Design and development of mini lab of fluid is necessary accomplished to support activity of collecting data. The references are used in the study of literature for design this research object, such as book, journal and other internet sources. In the process, there are some discussion between preceptor lecturer and the student whose charge in research of mini fluid lab. Based on the calculation of weight forces, the table uses hollow iron in dimension 60x40x4. By using the sentrifugal pump, which has flow capacity of 9 m3/h and total head of 5 m. Also, the galvanic pipe with dimension 1 ½ inch. In addition, other specifications are valve with ball type and the tank in capacity of 300 L. For setting the flow speed of pump is by using VSD (Variable Speed Drive) and AVR (Analog Voltage Regulator) as component for voltage adjusment.
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Fatahian, Hossein, Hesamoddin Salarian, Majid Eshagh Nimvari, and Esmaeel Fatahian. "NUMERICAL STUDY OF THERMAL CHARACTERISTICS OF FUEL OIL-ALUMINA AND WATER-ALUMINA NANOFLUIDS FLOW IN A CHANNEL IN THE LAMINAR FLOW." IIUM Engineering Journal 19, no. 1 (June 1, 2018): 251–69. http://dx.doi.org/10.31436/iiumej.v19i1.857.
Full textAbstract:
The present study investigated the thermal effects of the use of nanoparticles in the fuel-oil and water-based fluids, as well as the numerical simulation of laminar flow of fuel-oil-alumina and the water-alumina nanofluids in a channel. A second order discretization method was used for solving equations and a SIMPLE algorithm was applied for pressure-velocity coupling using Fluent. Effect of nanoparticle volume fraction and particles size in different Reynolds numbers (900≤Re≤2100) on the convective heat transfer coefficient was studied. The simulation was conducted for three different volume fractions and particle sizes in the laminar flow under constant heat flux. The results showed that adding nanoparticles to the base fluid caused an increase in the thermal conductivity ratio of the fluid, which was observed to a greater degree in the fuel oil-alumina nanofluid than in the water-alumina nanofluid. The increase in nanoparticle volume fraction caused an increase in the convective heat transfer coefficient and the Nusselt number of the nanofluids. The significant point of this study was that in the same volume fraction, the effect of adding alumina nanoparticles to the fuel-oil-based fluid had more effect than adding these particles to water-based fluid, while the effect of increasing the Reynolds number in the water-alumina nanofluid on convective heat transfer coefficient was greater than the fuel-oil-alumina. Also, in the same Reynolds number and volume fraction with increasing size of nanoparticles, the value of the convective heat transfer coefficient was decreased. The results of this study can be used in refineries and petrochemical industries where the fuel-oil fluid flows in the channels. ABSTRAK: Kajian ini adalah bagi mengkaji kesan haba terhadap penggunaan bahan bakar-minyak dan cecair asas-air dalam nanopartikel, juga menjalankan simulasi pengiraan aliran laminar bahan bakar-minyak-alumina dan cecair-nano air-alumina dalam saluran. Kaedah berasingan kelas kedua telah digunakan bagi menyelesaikan persamaan dan algoritma SIMPLE telah diaplikasikan dalam gandingan kelajuan-tekanan menggunakan Fluent. Kesan jumlah pecahan nanopartikel dan pelbagai bilangan saiz zarah dalam bilangan Reynolds (900≤Re≤2100) pada pekali pemindahan haba perolakan telah dikaji. Simulasi telah dijalankan pada tiga pecahan isipadu berlainan dan pada zarah dalam aliran laminar dengan fluks haba tetap. Hasil kajian menunjukkan bahawa dengan penambahan nanopartikel dalam cecair-asas menyebabkan peningkatan nisbah daya pengaliran haba cecair pada cecair-nano bahan bakar-minyak-alumina melebihi daripada cecair-nano air-alumina. Penambahan pada pecahan isipadu nanopartikel ini menyebabkan peningkatan pada nilai pekali pemindahan haba perolakan dan bilangan Nusselt dalam cecair-nano. Perkara penting dalam kajian ini adalah pada pecahan isipadu sama, kesan penambahan nanopartikel alumina kepada cecair berasaskan minyak mempunyai kesan yang lebih besar daripada penambahan zarah-zarah ini kepada cecair berasaskan air. Pada masa sama, kesan peningkatan bilangan Reynolds dalam cecair-nano air-alumina pada pekali pemindahan haba perolakan lebih besar daripada kesan peningkatan bahan bakar-minyak-alumina. Selain itu, pada bilangan Reynolds yang sama dan dengan peningkatan saiz nanopartikel pecahan isipadu, nilai pekali pemindahan haba perolakan turut menurun. Hasil kajian ini boleh digunakan dalam industri penapisan dan petrokimia di mana bahan bakar cecair minyak mengalir dalam saluran.
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Yangfi, Junjie. "Technology Focus: Hydraulic Fracturing Modeling (November 2021)." Journal of Petroleum Technology 73, no. 11 (November 1, 2021): 64. http://dx.doi.org/10.2118/1121-0064-jpt.
Full textAbstract:
In the past decades, the success of unconventional hydrocarbon resource development can be attributed primarily to the improved understanding of fracture systems, including both hydraulically induced fractures and natural fracture networks. To tackle the fracture characterization problem, several recent papers have provided novel insights into fracture modeling technique. Because of the complex nature and heterogeneity of rock discontinuity, fabric, and texture, the fracture-modeling process typically suffers from limited data availability. Research shows that modeling results reached without interrogation of high-resolution petrophysical and geomechanical data can mislead because the fluid flow is actually controlled by fine-scale rock properties. A more-reliable fracture geometry can be obtained from an enhanced modeling process that preserves the signature from high-frequency data. Advanced techniques to model fracturing processes with proppant transportation and thermodynamics require even more-sophisticated simulation and computation power. When the subsurface is too puzzling to be described by a physical model and existing data, machine learning and artificial intelligence can be adapted as a practical alternative to interpret complex fracture systems. Taking a discrete fracture network (DFN) as an example, a data-driven approach has been introduced to learn from outcrop, borehole imaging, core computed tomography scan, and seismic data to recognize stratigraphic bedding, faults, subseismic fractures, and hydraulic fractures. Input data can be collected by hand, 3D stereophotogrammetry, or drone. When upscaling DFN into a coarse grid for reservoir simulation, deep-learning techniques such as convolutional neuron networks can be used to populate fracture properties into a dual-porosity/dual-permeability model approved to yield high accuracy compared with a fine-grid model. Furthermore, the new techniques greatly extend the application of fracture modeling in the arena of the energy transition, such as in geothermal optimization. Recommended additional reading at OnePetro: www.onepetro.org. SPE 203927 - Numerical Simulation of Proppant Transport in Hydraulically Fractured Reservoirs by Seyhan Emre Gorucu, Computer Modelling Group, et al. SPE 202679 - Deep-Learning Approach To Predict Rheological Behavior of Supercritical CO2 Foam Fracturing Fluid Under Different Operating Conditions by Shehzad Ahmed, Khalifa University of Science and Technology, et al. SPE 203983 - A 3D Coupled Thermal/Hydraulic/Mechanical Model Using EDFM and XFEM for Hydraulic-Fracture-Dominated Geothermal Reservoirs by Xiangyu Yu, Colorado School of Mines, et al.