Journal articles: 'Experimental methods in fluid flow'

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Lund, Bjørnar, Ali Taghipour, Jan David Ytrehus, and Arild Saasen. "Experimental Methods for Investigation of Drilling Fluid Displacement in Irregular Annuli." Energies 13, no. 19 (October 6, 2020): 5201. http://dx.doi.org/10.3390/en13195201.

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Experimental methods are still indispensable for fluid mechanics research, despite advancements in the modelling and computer simulation field. Experimental data are vital for validating simulations of complex flow systems. However, measuring the flow in industrially relevant systems can be difficult for several reasons. Here we address flow measurement challenges related to cementing of oil wells, where main experimental issues are related to opacity of the fluids and the sheer size of the system. The main objective is to track the propagation of a fluid-fluid interface during a two-fluid displacement process, and thereby to characterize the efficiency of the displacement process. We describe the implementation and use of an array of electrical conductivity probes, and demonstrate with examples how the signals can be used to recover relevant information about the displacement process. To our knowledge this is the most extensive use of this measurement method for studying displacement in a large-scale laboratory setup. Optical measurements and visual observations are challenging and/or costly in such large-scale systems, but can still provide qualitative information as shown in this article. Using electrical conductivity probes is a robust and fairly low-cost experimental method for characterizing fluid-fluid displacement in large-scale systems.

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Wakimoto, Tatsuro, Koichi Araga, and Kenji Katoh. "OS22-10 Simultaneous Determination of Micelle Structure and Turbulent Transition in Drag-Reducing Surfactant Solution Flow using Fluorescence Probe Method(Fluid Flow and Hydrodynamic Forces,OS22 Experimental method in fluid mechanics,FLUID AND THERMODYNAMICS)." Abstracts of ATEM : International Conference on Advanced Technology in Experimental Mechanics : Asian Conference on Experimental Mechanics 2015.14 (2015): 274. http://dx.doi.org/10.1299/jsmeatem.2015.14.274.

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Kaminsky, R. D. "Predicting Single-Phase and Two-Phase Non-Newtonian Flow Behavior in Pipes." Journal of Energy Resources Technology 120, no. 1 (March 1, 1998): 2–7. http://dx.doi.org/10.1115/1.2795006.

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Improved and novel prediction methods are described for single-phase and two-phase flow of non-Newtonian fluids in pipes. Good predictions are achieved for pressure drop, liquid holdup fraction, and two-phase flow regime. The methods are applicable to any visco-inelastic non-Newtonian fluid and include the effect of surface roughness. The methods utilize a reference fluid for which validated models exist. For single-phase flow, the use of Newtonian and power-law reference fluids are illustrated. For two-phase flow, a Newtonian reference fluid is used. Focus is given to shear-thinning fluids. The approach is theoretically based and is expected to be more accurate for large, high-pressure pipelines than present correlation methods, which are all primarily based on low-pressure, small-diameter pipe experimental data.

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Yeung, Hoi C., and Paulo C. R. Lima. "Modeling of Pig Assisted Production Methods." Journal of Energy Resources Technology 124, no. 1 (March 1, 2002): 8–13. http://dx.doi.org/10.1115/1.1446474.

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More and more transient gas-liquid operations in pipes have been successfully applied in the oil and gas industry. Pigging operation in two-phase pipelines to remove liquid accumulation or for cleaning purpose is an important transient operation. Another important operation is the injection of gas to transport the accumulated liquid in the pipeline to process facilities. Analysis of such transient two-phase flow in a pipeline is necessary not only for designing the liquid and gas handling facilities, but also for establishing safe operating procedures. In pipeline-riser systems, such operations cause even more severe change in flow conditions. A two-fluid model has been developed to determine the transient behavior of fluids during these operations. A one-dimensional set of equations for bubble/mist, annular and stratified flows has been derived. Slug flows were modeled as a combination of the foregoing. Semi-implicit finite difference schemes were used to solve the initial and boundary value problem for each phase of the pigging process: gas/pig injection, gas shut-in, slug production, and gas flow out of the system. An extensive experimental program was carried out to acquire two-phase transient flow and pigging data on a 69-m-long, 9.9-m-high, 50-mm-dia pipeline-riser system. A computer based data acquisition system was used to obtain rapidly changing and detailed information of the flow behavior during tests. The model compared well with the experimental data for characteristics such as inlet pressure, hold-up, and pig velocity. Liquid production efficiencies for different operations were compared.

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Ajeeb, Wagd, Monica S. A. Oliveira, Nelson Martins, and S. M. Sohel Murshed. "Numerical approach for fluids flow and thermal convection in microchannels." Journal of Physics: Conference Series 2116, no. 1 (November 1, 2021): 012049. http://dx.doi.org/10.1088/1742-6596/2116/1/012049.

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Abstract The heat transfer performance of conventional thermal fluids in microchannels is an attractive method for cooling devices such as microelectronic applications. Computational fluid dynamics (CFD) is a very significant research technique in heat transfer studies and validated numerical models of microscale thermal management systems are of utmost importance. In this paper, some literature studies on available numerical and experimental models for single-phase and Newtonian fluids are reviewed and methods to tackle laminar fluid flow through a microchannel are sought. A few case studies are selected, and a numerical simulation is performed to obtain fluid flow behaviour within a microchannel, to test the level of accuracy and understanding of the problem. The numerical results are compared with relevant experimental results from the literature and a proper methodology for numerical investigation of single-phase and Newtonian fluid in laminar flow convection heat transfer in microscale heat exchangers is defined.

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du Roure, Olivia, Anke Lindner, Ehssan N. Nazockdast, and Michael J. Shelley. "Dynamics of Flexible Fibers in Viscous Flows and Fluids." Annual Review of Fluid Mechanics 51, no. 1 (January 5, 2019): 539–72. http://dx.doi.org/10.1146/annurev-fluid-122316-045153.

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The dynamics and deformations of immersed flexible fibers are at the heart of important industrial and biological processes, induce peculiar mechanical and transport properties in the fluids that contain them, and are the basis for novel methods of flow control. Here we focus on the low–Reynolds number regime where advances in studying these fiber–fluid systems have been especially rapid. On the experimental side, this is due to new methods of fiber synthesis, microfluidic flow control, and microscope-based tracking measurement techniques. Likewise, there have been continuous improvements in the specialized mathematical modeling and numerical methods needed to capture the interactions of slender flexible fibers with flows, boundaries, and each other.

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Pieprzyca, J., P. Warzecha, T. Merder, and M. Warzecha. "Experimental Methods of Validation for Numerical Simulation Results on Steel Flow through Tundish." Archives of Metallurgy and Materials 61, no. 4 (December 1, 2016): 2057–60. http://dx.doi.org/10.1515/amm-2016-0331.

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Abstract The article presents experimental results on the impact of tundish flow regulator influencing the liquid steel flow course. The research was conducted based on the hybrid modelling methods understood as a complementary use of Computational Fluid Dynamics (CFD) methods and physical modelling. Dynamic development of numerical simulation techniques and accessibility to highly advanced and specialized software causes the fact that these techniques are commonly used for solving problems related to liquid flows by using analytical methods. Whereas, physical modelling is an important cognitive tool in the field of empirical identification of these phenomena. This allows for peer review and specification of the researched problems. By exploiting these relationships, a comparison of the obtained results was performed in the form of residence time distribution (RTD) curves and visualization of particular types of liquid steel flow distribution zones in the investigated tundish.

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Fujimatsu, Takahiro, Mizuki Kito, and Kunikazu Kondo. "OS22-3 Gas-Liquid Two Phase Flow in a Horizontal Pipe with a Sudden Contraction(Thermal Transport Measurements and Multiphase Flow,OS22 Experimental method in fluid mechanics,FLUID AND THERMODYNAMICS)." Abstracts of ATEM : International Conference on Advanced Technology in Experimental Mechanics : Asian Conference on Experimental Mechanics 2015.14 (2015): 267. http://dx.doi.org/10.1299/jsmeatem.2015.14.267.

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Kawaguchi, Tatsuya, Ryosuke Takagi, and Sohei Ueda. "OS22-9 Analysis of Drag Force on a Sphere Influenced by Other Objects Indirectly(Fluid Flow and Hydrodynamic Forces,OS22 Experimental method in fluid mechanics,FLUID AND THERMODYNAMICS)." Abstracts of ATEM : International Conference on Advanced Technology in Experimental Mechanics : Asian Conference on Experimental Mechanics 2015.14 (2015): 273. http://dx.doi.org/10.1299/jsmeatem.2015.14.273.

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Longatte, E., Z. Bendjeddou, and M. Souli. "Application of Arbitrary Lagrange Euler Formulations to Flow-Induced Vibration Problems." Journal of Pressure Vessel Technology 125, no. 4 (November 1, 2003): 411–17. http://dx.doi.org/10.1115/1.1613950.

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Most classical fluid force identification methods rely on mechanical structure response measurements associated with convenient data processes providing turbulent and fluid-elastic forces responsible for possible vibrations and damage. These techniques provide good results; however, they often involve high costs as they rely on specific modelings fitted with experimental data. Owing to recent improvements in computational fluid dynamics, numerical simulation of flow-induced structure vibration problems is now practicable for industrial purposes. As far as flow structure interactions are concerned, the main difficulty consists in estimating numerically fluid-elastic forces acting on mechanical components submitted to turbulent flows. The point is to take into account both fluid effects on structure motion and conversely dynamic motion effects on local flow patterns. This requires a code coupling to solve fluid and structure problems in the same time. This ability is out of limit of most classical fluid dynamics codes. That is the reason why recently an improved numerical approach has been developed and applied to the fully numerical prediction of a flexible tube dynamic response belonging to a fixed tube bundle submitted to cross flows. The methodology consists in simulating at the same time thermo-hydraulics and mechanics problems by using an Arbitrary Lagrange Euler (ALE) formulation for the fluid computation. Numerical results turn out to be consistent with available experimental data and calculations tend to show that it is now possible to simulate numerically tube bundle vibrations in presence of cross flows. Thus a new possible application for ALE methods is the prediction of flow-induced vibration problems. The full computational process is described in the first section. Classical and improved ALE formulations are presented in the second part. Main numerical results are compared to available experimental data in section 3. Code performances are pointed out in terms of mesh generation process and code coupling method.

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Semikhina, Lyudmila P., Daniil D. Korovin, and Dmitry V. Semikhin. "Analysis of theoretical methods for interpretation the non-Newtonian fluids viscosity experimental data." Tyumen State University Herald. Physical and Mathematical Modeling. Oil, Gas, Energy 8, no. 4 (2022): 95–110. http://dx.doi.org/10.21684/2411-7978-2022-8-4-95-110.

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Using a rotary viscometer Brookfield DV-II+Pro, the viscosity of an almost one-component (1-2% impurity) sample of synthanol ALM-7 was studied. In the presented work, this reagent is use as a sample of a highly viscous non-Newtonian fluid and a concentrated micellar disperse system, the particles of the dispersed phase in which are micelles from molecules of this surfactant with dimensions less than 10 nm. Using the example of such a fluid, it is shown that the decrease in viscosity observed in it, typical for dispersed systems, as the shear rate increases, is accompanied by an increase in the activation energy of the viscous flow, which is inconsistent with the Arrhenius and Frenkel equation. The reason is that these equations do not take into account the changes in entropy ∆S during the viscous flow of the non-Newtonian fluid, the value of which actually determines the sign of the change in the viscosity of the non-Newtonian fluid with increasing velocity or shear stress. The only way to calculate ∆S now based on the use of the Eyring equation. However, for the correct calculation of ∆S by the temperature dependence of the dynamic viscosity of the non-Newtonian fluid and the Eyring equation, an independent correct way of finding the value of the preexponent B in this equation is necessary. The article analyzes the methods described in the literature for calculating the values of B, including those proposed by Henry Eyring himself. As a result, it was revealed that only the experimental method we developed for estimating the values of B corresponds to real processes in the non-Newtonian fluid, since only with such calculations does an increase in temperature and shear deformations lead to values of ∆S > 0, indicating the destructive effect of these factors on the non-Newtonian fluid. It is shown that other methods of calculating B can lead to incorrect values of ∆S < 0 and, as a consequence, erroneous conclusions about the processes occurring inside the non-Newtonian fluid.

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Inagaki, Ayumu, Ryohei Mizobe, and Hidemi Yamada. "OS22-8 Wavelet Analysis of Vortex Shedding From a Circular Cylinder Supported by End Plates(Fluid Flow and Hydrodynamic Forces,OS22 Experimental method in fluid mechanics,FLUID AND THERMODYNAMICS)." Abstracts of ATEM : International Conference on Advanced Technology in Experimental Mechanics : Asian Conference on Experimental Mechanics 2015.14 (2015): 272. http://dx.doi.org/10.1299/jsmeatem.2015.14.272.

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Terzis, Alexandros, Pavlos K. Zachos, Bernard A. Charnley, and Anestis I. Kalfas. "Application of oil and dye flow visualization in incompressible turbomachinery flows." E3S Web of Conferences 345 (2022): 02003. http://dx.doi.org/10.1051/e3sconf/202234502003.

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Flow visualization is one of many available tools in experimental fluid mechanics and is used from the primary stages of fluid mechanics research in order to identify the physical sizes and locations of the flow features under consideration. Most of the fluids used in engineering applications are transparent (water, air, etc) and flow visualization techniques are used in order to make their flow patterns visible. Simple flow visualization experiments are relatively inexpensive and they can be easily implemented providing with a first feeling of the characteristics of the flow domain. Subsequently, flow visualization techniques are of great applicability in complex flow fields and especially in turbomachinery applications where the flow is characterized by three dimensional and secondary flow patterns. In general, fluid motion can be visualized by surface flow visualization, by particle tracer methods or by optical methods. The former flow visualization technique reveals the streamlines of fluid flows around a solid surface. In this paper flow visualization techniques applied in two different cases of experimental testing (fans in crossflow and cascade experiment) are presented. In both cases, the mixture of paint was prepared using a highly volatile light mineral or heavy machine oil of viscosities of approximately 100cP and 200cP, respectively, together with very fine pigments of Titanium Dioxide (TiO2) or fluorescein sodium in various colors. After the preparation of the mixture, a homogenous thin film was applied onto the whole plate surface by painting it with a soft brush. The air stream which flows over the surface of the plate, modifies the concentration and the homogeneity of the oil film, according to the flow conditions very close to the wall. The film was dried by the airflow and photographed for further consideration while the time taken for drying depended on the wind tunnel velocity as well as, on the pigmentation of the mixture. Successful and un-successful flow visualization tests are herein presented while each case is respectively commented as far as the mixtures, the proportions used and the application onto the rigs are concerned.

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Dethloff, Manuel, Hermann Seitz, and Marc Dangers. "Numerical flow simulation methods and additive manufacturing methods for the development of a flow optimised design of a novel point-of-care diagnostic device." Current Directions in Biomedical Engineering 3, no. 2 (September 7, 2017): 619–22. http://dx.doi.org/10.1515/cdbme-2017-0129.

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AbstractFor the development of a novel, user-friendly and low cost point-of-care diagnostic device for the detection of disease specific biomarker a flow optimised design of the test system has to be investigated. The resulting test system is characterised by a reduced execution period, a reduction of execution steps and an integrated waste management. Based on previous results, the current study focused on the design implementation of the fluidic requirements, e. g. tightness, inside the test device. With the help of fluid flow simulations (CFD – computational fluid dynamics) the flow behaviour inside the test device was analysed for different designs and arrangements. Prototypes generated from additive manufacturing technologies (PolyJet modeling) are used for validating the simulation results and further experimental tests.

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Gordon, Robert, and Mohammed S. Imbabi. "CFD Simulation and Experimental Validation of a New Closed Circuit Wind/Water Tunnel Design." Journal of Fluids Engineering 120, no. 2 (June 1, 1998): 311–18. http://dx.doi.org/10.1115/1.2820650.

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A new closed-circuit wind/water tunnel to support flow visualization research was designed and constructed at The University of Aberdeen. Review of existing closed-circuit tunnel designs revealed that they are large, expensive, difficult to set up and maintain, and typically employ a single working fluid. Key objectives of the work reported here were to reduce the overall cost and size of the tunnel, facilitate the use of alternative working fluids (air or water), and provide high quality flow within the test section. Conventional design methods were used initially, and computational fluid dynamics (CFD) was then employed to simulate the flow within critical sections of the tunnel. The results from CFD played a decisive role in identifying the modifications needed to achieve the compact, cost-effective tunnel design eventually built and tested. Flow quality within the test section was established using measured velocity profiles, and these are also presented.

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Thongsukh, Vorasruang, Chanida Kositratana, and Aree Jandonpai. "Effect of Fluid Flow Rate on Efficacy of Fluid Warmer: An In Vitro Experimental Study." Anesthesiology Research and Practice 2018 (July 8, 2018): 1–4. http://dx.doi.org/10.1155/2018/8792125.

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Introduction. In patients who require a massive intraoperative transfusion, cold fluid or blood transfusion can cause hypothermia and potential adverse effects. One method by which to prevent hypothermia in these patients is to warm the intravenous fluid before infusion. The aim of this study was to determine the effect of the fluid flow rate on the efficacy of a fluid warmer. Methods. The room air temperature was controlled at 24°C. Normal saline at room temperature was used for the experiment. The fluid was connected to an infusion pump and covered with a heater line, which constantly maintained the temperature at 42°C. The fluid temperature after warming was measured by an insulated thermistor at different fluid flow rates (100, 300, 600, 900, and 1200 mL/h) and compared with the fluid temperature before warming. Effective warming was defined as an outlet fluid temperature of >32°C. Results. The room temperature was 23.6°C ± 0.9°C. The fluid temperature before warming was 24.95°C ± 0.5°C. The outlet temperature was significantly higher after warming at all flow rates (p<0.001). The increases in temperature were 10.9°C ± 0.1°C, 11.5°C ± 0.1°C, 10.2°C ± 0.1°C, 10.1°C ± 0.7°C, and 8.4°C ± 0.2°C at flow rates of 100, 300, 600, 900, and 1200 mL/h, respectively. The changes in temperature among all different flow rates were statistically significant (p<0.001). The outlet temperature was >32°C at all flow rates. Conclusions. The efficacy of fluid warming was inversely associated with the increase in flow rate. The outlet temperature was <42°C at fluid flow rates of 100 to 1200 mL/h. However, all outlet temperatures reached >32°C, indicating effective maintenance of the core body temperature by infusion of warm fluid.

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Vempati, Bhadraiah, Mahesh V. Panchagnula, Alparslan Öztekin, and Sudhakar Neti. "Numerical Investigation of Liquid-Liquid Coaxial Flows." Journal of Fluids Engineering 129, no. 6 (December 8, 2006): 713–19. http://dx.doi.org/10.1115/1.2734223.

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This paper presents numerical results of the interfacial dynamics of axisymmetric liquid-liquid flows when the denser liquid is injected with a parabolic inlet velocity profile into a coflowing lighter fluid. The flow dynamics are studied as a function of the individual phase Reynolds numbers, viscosity ratio, velocity ratio, Bond number, and capillary number. Unsteady, axisymmetric flows of two immiscible fluids have been studied using commercial software, FLUENT® with the combination of volume of fluid (VOF) and continuous surface force (CSF) methods. The flows have been categorized as “flow-accelerated regime (FAR) and “flow-decelerated regime” (FDR) based on acceleration/deceleration of the injected fluid. The injected jet diameter decreases when the average inlet velocity ratio is less than unity. The outer fluid velocity has a significant effect on the shape and evolution of the jet as it progresses downstream. As the outer liquid flow rate is increased, the intact jet length is stretched to longer lengths while the jet radius is reduced due to interfacial stresses. The jet radius appears to increase with increasing viscosity ratio and ratio of Bond and capillary numbers. The results of numerical simulations using FLUENT agree well with experimental measurements and the far-field self-similar solution.

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Svoboda, Dmitry, Igor Borshchev, Aleksandr Zharkovskii, Evgeniy Tvanov, and Arsentiy Klyuyev. "CFD computation of flow in the flow path of a torque flow pump." E3S Web of Conferences 207 (2020): 04005. http://dx.doi.org/10.1051/e3sconf/202020704005.

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The results are presented of numerical and experimental research of fluid flow in the flow path of a torque flow pump with specific speed ns ;: 55. The 3D methods of CFD have been shown to allow for predicting energy characteristics of this type of pumps with a sufficient accuracy. According to the results of flow visualization the work process has been analysed and conclusions drawn to enhance TFP efficiency.

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Krapivin, I. I., A. V. Belyaev, and A. V. Dedov. "Experimental Investigation of Boiling Heat Transfer in Freons Subjected to Forced Flow." Herald of the Bauman Moscow State Technical University. Series Natural Sciences, no. 4 (103) (August 2022): 59–79. http://dx.doi.org/10.18698/1812-3368-2022-4-59-79.

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At the moment there exist no methods for computing the boiling heat transfer coefficient in a fluid flow that could take into account the diversity of flow modes for a wide range of flow parameters. The majority of experimental and analytical studies were performed at low reduced pressures. Noticeably fewer investigations were carried out at high reduced pressures. At present, there are numerous empirical heat transfer computation methods developed for various freons at moderate reduced pressures and mass velocities. There also exist dedicated formulas for computing heat transfer in mini- and microchannels, obtained at low reduced pressures. Power and refrigeration systems could be fitted with mini-channel heat exchangers with custom working fluids subjected to high or moderate pressures. It is necessary to verify whether the existing methods for computing heat transfer are valid at higher reduced pressures, up to pr ≈ 0.6, in a channel with a hydraulic diameter of d ≈ 1 mm. The paper presents an overview of existing methods for calculating the heat transfer coefficient in two-phase flows; we then generalise these and compare their results to our own experimental data. We obtained said experimental data at the reduced pressures of pr = p/pcr = 0.43 and 0.56 in the mass velocity range of G = 200--1500 kg/(m2 · s). The paper describes our test bench and the experimental procedure

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Jiang, Shouyan, and Chengbin Du. "Coupled Finite Volume Methods and Extended Finite Element Methods for the Dynamic Crack Propagation Modelling with the Pressurized Crack Surfaces." Shock and Vibration 2017 (2017): 1–16. http://dx.doi.org/10.1155/2017/3751340.

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We model the fluid flow within the crack as one-dimensional flow and assume that the flow is laminar; the fluid is incompressible and accounts for the time-dependent rate of crack opening. Here, we discretise the flow equation by finite volume methods. The extended finite element methods are used for solving solid medium with crack under dynamic loads. Having constructed the approximation of dynamic extended finite element methods, the derivation of governing equation for dynamic extended finite element methods is presented. The implicit time algorithm is elaborated for the time descritisation of dominant equation. In addition, the interaction integral method is given for evaluating stress intensity factors. Then, the coupling model for modelling hydraulic fracture can be established by the extended finite element methods and the finite volume methods. We compare our present numerical results with our experimental results for verifying the proposed model. Finally, we investigate the water pressure distribution along crack surface and the effect of water pressure distribution on the fracture property.

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Mier, Frank, Raj Bhakta, Nicolas Castano, John Garcia, and Michael Hargather. "Experimental Measurement of Steady and Transient Liquid Coiling with High-Speed Video and Digital Image Processing." Fluids 3, no. 4 (December 15, 2018): 107. http://dx.doi.org/10.3390/fluids3040107.

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Liquid coiling occurs as a viscous fluid flows into a stagnant reservoir causing a localized accumulation of settling material, which coils into a stack as it accumulates. These coiling flows are broadly characterized into three primary coiling regimes of viscous, gravitational, or inertial coiling, based on the velocity of the falling fluid, the height of the fall, the radius of the fluid rope, the stack height, and the fluid properties including viscosity. A computer-controlled flow delivery apparatus was developed here to produce precisely controlled flow conditions to study steady and transitional coiling regimes with independently varied parameters. Data were recorded using high-speed digital video cameras and a purpose-built digital image processing routine to extract rope and stack dimensions as well as time-resolved coiling frequency. The precision of the setup and data analysis methods allowed a detailed study of the transition between gravitational and inertial flow regimes. The results show a smooth transition between the regimes, with no evidence of the inertial-gravitational regime. Unsteady coiling was able to be momentarily produced by applying a perturbation to the system, but the unstable regime quickly decayed to either the base inertial or gravitational regime.

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Kovalev, Vasyl, Volodumur Kalyuzhny, and Vadum Gornostay. "Physical model of fluid flows in spacecraft tank." Mechanics and Advanced Technologies 5, no. 2 (November 9, 2021): 212–17. http://dx.doi.org/10.20535/2521-1943.2021.5.2.126106.

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The results of an experimental study of liquid fuel flows in the tanks of a spacecraft during its rotation are presented. The analysis of structure and character of flows development on time is carried out, variants of graphic dependences approximation are offered. Graphical diagrams are presented, according to which it is convenient to present a three-dimensional nonlinear picture of non-stationary axisymmetric flow in a spherical reservoir, as well as methods of influencing flows with the help of internal baffles. Estimation of the obtained experimental data probability testifies to the rather high quality of the measurement results and the constructed picture of the currents in the spherical tank with internal baffles.

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Sawada, Ikuo, Hiroyuki Tanaka, and Masahiro Tanaka. "Status of Computational Fluid Dynamics and Its Application to Materials Manufacturing." MRS Bulletin 19, no. 1 (January 1994): 14–19. http://dx.doi.org/10.1557/s088376940003880x.

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Computational fluid dynamics was born principally in the aerospace field as a method for fluid flow and heat transfer research methods following experimental and analytical approaches. Along with progress in the cost performance of computers, computational fluid dynamics is now establishing itself as a tool to improve production processes and product quality in the steel, nonferrous metals, glass, plastics, and composite materials industries.Materials manufacturers use computational fluid dynamics for diverse purposes:1. Reduction in experimental conditions and costs;2. Detailed analysis of mechanisms with multifaceted information unobtainable through experimentation;3. Universal tool for scale-up; and4. Evaluation of novel processes.It can be readily imagined that accuracy, flexibility, and other requirements of computational fluid dynamics should vary with specific applications.Fluids generally observed in materials manufacturing processes are molten materials such as metal, glass, and plastics, and gases for stirring and refining. In the flow of such fluids, materials quality and process characteristics are governed by the following:1. Transport phenomena in the bulk region (where fluid flow is normally turbulent);2. Chemical reaction at interfaces;3. Transport phenomena in boundary layers near the interfaces; and4. Complex coupled phenomena (heat transfer, diffusion, chemical reaction, phase transformation like solidification, free surface, electromagnetic force, and bubble flow).

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Soper, David, Dominic Flynn, Chris Baker, Adam Jackson, and Hassan Hemida. "A comparative study of methods to simulate aerodynamic flow beneath a high-speed train." Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit 232, no. 5 (October 5, 2017): 1464–82. http://dx.doi.org/10.1177/0954409717734090.

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The introduction of dedicated high-speed railway lines around the world has led to issues associated with running trains at very high speeds. Aerodynamic effects proportionally increase with train speed squared; consequently, at higher speeds aerodynamic effects will be significantly greater than those of trains travelling at lower speeds. On ballasted track beds, the phenomenon in which ballast particles become airborne during the passage of a high-speed train has led to the need for understanding the processes involved in train and track interaction (both aerodynamical and geotechnical). The difficulty in making full-scale aerodynamic measurements beneath a high-speed train has created the requirement to be able to accurately simulate these complex aerodynamic flows at the model scale. In this study, the results of moving-model tests and numerical simulations were analysed to determine the performance of each method for simulating the aerodynamic flow underneath a high-speed train. Validation was provided for both cases by juxtaposing the results against those from full-scale measurements. The moving-model tests and numerical simulations were performed at the 1/25th scale. Horizontal velocities from the moving-model tests and computational fluid dynamics simulations were mostly comparable except those obtained close to the ballast. In this region, multi-hole aerodynamic probes were unable to accurately measure velocities. The numerical simulations were able to resolve the flow to much smaller turbulent scales than could be measured in the experiments and showed an overshoot in peak velocity magnitudes. Pressure and velocity magnitudes were found to be greater in the numerical simulations than in the experimental tests. This is thought to be due to the influence of ballast stones in the experimental studies allowing the flow to diffuse through them, whereas in the computational fluid dynamics simulations, the flow stagnated on a smooth non-porous surface. Additional validation of standard deviations and turbulence intensities found good agreement between the experimental data but an overshoot in the numerical simulations. Both moving model and computational fluid dynamics techniques were shown to be able to replicate the flow development beneath a high-speed train. These techniques could therefore be used as a method to model underbody flow with a view to train homologation.

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Hadiningrum, Kunlestiowati, Ratu Fenny Muldiani, and Defrianto Pratama. "Improving Understanding of the Concept of the Effect of Temperature on Fluid Flow Characteristics Through Experimental Methods for Engineering Students." Jurnal Geliga Sains: Jurnal Pendidikan Fisika 10, no. 2 (January 10, 2023): 144. http://dx.doi.org/10.31258/jgs.10.2.144-153.

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This research is motivated by the high need for dynamic fluid concepts in the industrial world. to research the increased understanding of the concept of the influence of temperature on the characteristics of fluid flow which is part of the subject matter of fluid dynamics, an experimental module was prepared based on the optimization results of the appropriate physical quantities through testing of experimental instruments. The research aims to know the understanding the concept of the influence of temperature on the characteristics of fluid flow through experimental activities, to support the learning of dynamic fluid concepts for engineering students at the Bandung State Polytechnic. The research method uses quasi-experimental research, with experimental class learning treatment through theory and experimentation, while in the control class only through theory. To examine the effect of the experimental method on learning outcomes of conceptual understanding with 7 indicators using simple statistical analysis techniques. The results of the data analysis obtained an increase in understanding of the concept of the group of students who carried out experimental activities higher than the group of students who only received learning in theory class. The results of the normality test for the experimental class and control classes stated that the pre-test and post-test data were normally distributed. The results of the accumulated percentage of respondents' questionnaires, as many as 92.1% of respondents gave positive responses (strongly agreed and agreed) on quality and only 7.9% of respondents gave ordinary responses. Based on the average N-Gain, it was obtained that the experimental class had a greater N-Gain value than the control class, then based on the t-test, students' understanding of the concepts of the experimental class and the control class had a significant difference after being given treatment, it can be interpreted that the class that received experimental learning was more have a higher conceptual understanding.

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Trevisan, B. P., and W. M. C. Dourado. "EXPERIMENTAL STUDY OF THE INLET FLOW IN A NON-PREMIXED COMBUSTION CHAMBER." Revista de Engenharia Térmica 19, no. 1 (September 9, 2020): 72. http://dx.doi.org/10.5380/reterm.v19i1.76437.

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The evaluation, validation and development of the models used in computation fluid dynamics requires the availability of experimental data for which the boundary conditions, especially the conditions of the inlet flow, are well defined. Laser diagnostics techniques provide experimental data used in computational fluid dynamics and are a powerful tool for measurements of the mean properties and fluctuations of the turbulent flow because they are non-intrusive methods, with high repetition rate and high spatial and temporal resolution. Therefore, in the present work an experimental study of the inlet flow (inert and combusting flows) in a non-premixed combustion chamber is presented. The velocity measurements were carried out using a laser Doppler velocimeter at the entrance region of the combustion chamber. An asymmetry on the mean flow and an increase on the total velocity fluctuations with the increase of the equivalence ratio was observed. The major effect on the increase of the equivalence ratio was a presence of a coherent movement on large scales associated to the flame brush dynamics.

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Lopez-Santana, Gabriela, Andrew Kennaugh, and Amir Keshmiri. "Experimental Techniques against RANS Method in a Fully Developed Turbulent Pipe Flow: Evolution of Experimental and Computational Methods for the Study of Turbulence." Fluids 7, no. 2 (February 15, 2022): 78. http://dx.doi.org/10.3390/fluids7020078.

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Fully developed turbulent flow in a pipe was studied by considering experimental and computational methods. The aim of this work was to build on the legacy of the University of Manchester, which is widely regarded as the birthplace of turbulence due to the pioneering work of the prominent academic Professor Osborne Reynolds (1842–1912), by capturing the evolution of fluid turbulence analysis tools over the last 100 years. A classical experimental apparatus was used to measure the mean velocity field and wall shear stress through four historical techniques: static pressure drop; mean square signals measured from a hot-wire; Preston tube; and Clauser plot. Computational Fluid Dynamics (CFD) was used to simulate the pipe flow, utilizing the Reynolds-averaged Navier–Stokes (RANS) method with different two-equation turbulence models. The performance of each approach was assessed to compare the experimental and computational methods. This comparison revealed that the numerical results produced a close agreement with the experiments. The finding shows that, in some cases, CFD simulations could be used as alternative or complementary methods to experimental techniques for analyzing fully developed turbulent pipe flow.

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Kaunga, Damson, Raj Patel, and Iqbal M. Mujtaba. "Humidification-dehumidification desalination process: Performance evaluation and improvement through experimental and numerical methods." Thermal Science and Engineering Progress 27 (January 2022): 101159. http://dx.doi.org/10.1016/j.tsep.2021.101159.

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Bandi, M. M. "Tension grips the flow." Journal of Fluid Mechanics 846 (May 3, 2018): 1–4. http://dx.doi.org/10.1017/jfm.2018.301.

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Surface tension plays a dominant role in the formation and stability of soap films. It renders them both a quasi-two-dimensional fluid and an elastic membrane at the same time. The techniques for measuring the surface tension of the soap solution may very well apply to the static soap film, but how can the surface tension of a soap film be unintrusively measured, and what value would it assume? The answer, being at the intersection of physical chemistry, non-equilibrium physics and interfacial fluid dynamics, is not amenable to deduction via established methods. In a joint theoretical and experimental study, Sane et al. (J. Fluid Mech., vol. 841, 2018, R2) exploit elasticity theory to glean the answer through a simple, yet elegant framework.

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Knigge, Sara R., and Birgit Glasmacher. "Comparison between three in vitro methods to measure magnesium degradation and their suitability for predicting in vivo degradation." International Journal of Artificial Organs 41, no. 11 (May 13, 2018): 772–78. http://dx.doi.org/10.1177/0391398818772777.

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A lot of research has been done in the field of magnesium-based implant material. This study is focused on finding an explanation for the large disparity in results from similar experiments in literature. The hypothesis is that many different measurement protocols are used to quantify magnesium degradation and this leads to inconsistent results. Cylindrical, pure magnesium samples were used for this study. The degradation took place in revised simulated body fluid at 37°C. Hydrogen evolution was measured to quantify the degradation. Two commonly used experimental protocols were examined: static conditions and a fluid changing method. For static testing, the samples stayed in fluid. For the fluid changing method, the fluid was changed after 2 and 5 days of immersion. In addition, a new method with continuous fluid flow was established. After an initial phase, the results confirm that for all three methods, the degradation behavior differs strongly. The static condition results in a very slow degradation rate. The fluid change method leads to a similar behavior like the static condition except that the degradation was speeded up after the fluid changes. The continuous degradation is linear for a long period after the initial phase. In comparison with in vivo degradation behavior, the degradation process in continuous flow shows the best fitting. The accumulation of degradation products, especially the increasing pH value, has a strong inhibiting effect. This cannot be observed in vivo so that a constant experimental environment realizable by continuous flow is more suitable for magnesium-based implant material testing.

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Cheng, Chen, and Guang-Tao Zhang. "Deep Learning Method Based on Physics Informed Neural Network with Resnet Block for Solving Fluid Flow Problems." Water 13, no. 4 (February 5, 2021): 423. http://dx.doi.org/10.3390/w13040423.

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Solving fluid dynamics problems mainly rely on experimental methods and numerical simulation. However, in experimental methods it is difficult to simulate the physical problems in reality, and there is also a high-cost to the economy while numerical simulation methods are sensitive about meshing a complicated structure. It is also time-consuming due to the billion degrees of freedom in relevant spatial-temporal flow fields. Therefore, constructing a cost-effective model to settle fluid dynamics problems is of significant meaning. Deep learning (DL) has great abilities to handle strong nonlinearity and high dimensionality that attracts much attention for solving fluid problems. Unfortunately, the proposed surrogate models in DL are almost black-box models and lack interpretation. In this paper, the Physical Informed Neural Network (PINN) combined with Resnet blocks is proposed to solve fluid flows depending on the partial differential equations (i.e., Navier-Stokes equation) which are embedded into the loss function of the deep neural network to drive the model. In addition, the initial conditions and boundary conditions are also considered in the loss function. To validate the performance of the PINN with Resnet blocks, Burger’s equation with a discontinuous solution and Navier-Stokes (N-S) equation with continuous solution are selected. The results show that the PINN with Resnet blocks (Res-PINN) has stronger predictive ability than traditional deep learning methods. In addition, the Res-PINN can predict the whole velocity fields and pressure fields in spatial-temporal fluid flows, the magnitude of the mean square error of the fluid flow reaches to 10−5. The inverse problems of the fluid flows are also well conducted. The errors of the inverse parameters are 0.98% and 3.1% in clean data and 0.99% and 3.1% in noisy data.

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Zhu, Jianjun, Haiwen Zhu, Guangqiang Cao, Jiecheng Zhang, Jianlin Peng, Hattan Banjar, and Hong-Quan Zhang. "A New Mechanistic Model To Predict Boosting Pressure of Electrical Submersible Pumps Under High-Viscosity Fluid Flow with Validations by Experimental Data." SPE Journal 25, no. 02 (December 12, 2019): 744–58. http://dx.doi.org/10.2118/194384-pa.

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Summary As the second most widely used artificial-lift method in petroleum production (and first in accumulative production), electrical submersible pumps (ESPs) increase flow rates by converting kinetic energy to hydraulic pressure. ESPs are routinely characterized with water flow, and water performance curves are provided by the manufacturers (catalog curves) for designing ESP-based artificial-lift systems. However, the properties of hydrocarbon fluids are very different from those of water, especially the dynamic viscosities, which can significantly alter the ESP performance. Most of the existing methods to estimate ESP boosting pressure under high-viscosity fluid flow involve a strong empirical nature, and are derived by correlating experimental/field data with correction factors (e.g., Hydraulic Institute Standards 1955). A universally valid mechanistic model to calculate the ESP boosting pressure under viscous fluid flow is not yet available. In this paper, a new mechanistic model accounting for the viscosity effect of working fluids on ESP hydraulic performance is proposed, and it is validated with a large database collected from different types of ESPs. The new model starts from the Euler equations for characterizing centrifugal pumps, and introduces a conceptual best-match flow rate QBM, at which the outlet flow direction of the impeller matches the designed flow direction. The mismatch of velocity triangles, resulting from the varying liquid-flow rates, is used to derive the recirculation losses. Other head losses caused by flow-direction change, friction, leakage flow, and other factors. are incorporated into the new model as well. QBM is obtained by matching the predicted H-Q performance curve of an ESP with the catalog curves. Once QBM is determined, the ESP hydraulic head under viscous-fluid-flow conditions can be calculated. The specific speed (NS) of the studied ESPs in this paper ranges from 1,600 to 3,448, including one radial-type ESP and two mixed-type designs. The model-predicted ESP boosting pressure with water flow is found to match the catalog curves well if QBM is properly tuned. With high-viscosity fluid presence, the model predictions of ESP boosting pressure also agree well with the corresponding experimental data. For most calculation results within medium to high flow rates, the model prediction error is less than 15%. Unlike the empirical correlations that take experimental data points as inputs, the mechanistic model in this study does not require entering any experimental data, but can predict ESP boosting pressure under viscous fluid flow with a reasonable accuracy.

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Pasymi, Pasymi, Yogi W. Budhi, and Yazid Bindar. "Experimental and Numerical Investigations of Fluid Flow Behaviors in a Biomass Cyclone Burner." ASEAN Journal of Chemical Engineering 20, no. 1 (June 29, 2020): 88. http://dx.doi.org/10.22146/ajche.56708.

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A combination of the experimental and numerical methods was used to investigate the fluid flow behaviors in a proposed cyclone burner. Recirculation flow and pressure drop, two of the important fluid flow behaviors that affect the burner's performance, have been studied here. Experimentally, the recirculation flow phenomenon in the burner was observed through paper slices dynamic in a transparent burner, and pressure drop was measured using a tube manometer. Meanwhile numerically, the fluid flow behaviors were simulated using the standard k-e turbulence model, under Ansys-Fluent software. The simulation results showed that, at a certain value of inlet aspect ratio (RIA) and initial tangential intensity (IIT), especially for high IIT, the recirculation flow phenomenon was clearly observed in the center of the burner cylinder which closely resembles a tornado-tail. The indication of existence recirculation flow was also found from the experiment results. The study also exhibited that the results of simulated static pressure drop were closely approaching the experiment results, particularly for IIT values £ 4.3. The mean deviation of static pressure between the simulation and the experiment results, for a varied range of RIA and IIT,was about 15%. From the results above, it was obvious that fluid flow behaviors (recirculation flow and static pressure) in the proposed cyclone burner are greatly influenced by the RIA and IIT values, where the IIT effect was more significant compared to the RIA. This study also suggests that, the standard k-e turbulence model could be relied upon to well predict the behaviors of fluid flow in the proposed cyclone burner, at low to moderate swirl intensities.

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Silva-Leon, Jorge, and Andrea Cioncolini. "Experiments on Flexible Filaments in Air Flow for Aeroelasticity and Fluid-Structure Interaction Models Validation." Fluids 5, no. 2 (June 5, 2020): 90. http://dx.doi.org/10.3390/fluids5020090.

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Several problems in science and engineering are characterized by the interaction between fluid flows and deformable structures. Due to their complex and multidisciplinary nature, these problems cannot normally be solved analytically and experiments are frequently of limited scope, so that numerical simulations represent the main analysis tool. Key to the advancement of numerical methods is the availability of experimental test cases for validation. This paper presents results of an experiment specifically designed for the validation of numerical methods for aeroelasticity and fluid-structure interaction problems. Flexible filaments of rectangular cross-section and various lengths were exposed to air flow of moderate Reynolds number, corresponding to laminar and mildly turbulent flow conditions. Experiments were conducted in a wind tunnel, and the flexible filaments dynamics was recorded via fast video imaging. The structural response of the filaments included static reconfiguration, small-amplitude vibration, large-amplitude limit-cycle periodic oscillation, and large-amplitude non-periodic motion. The present experimental setup was designed to incorporate a rich fluid-structure interaction physics within a relatively simple configuration without mimicking any specific structure, so that the results presented herein can be valuable for models validation in aeroelasticity and also fluid-structure interaction applications.

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Shahid, Salman, Sharul Sham Dol, Abdul Qader Hasan, Omar Mustafa Kassem, Mohamed S. Gadala, and Mohd Shiraz Aris. "A Review on Electrical Submersible Pump Head Losses and Methods to Analyze Two-Phase Performance Curve." WSEAS TRANSACTIONS ON FLUID MECHANICS 16 (February 9, 2021): 14–31. http://dx.doi.org/10.37394/232013.2021.16.3.

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Electrical submersible pumps (ESP) are referred to as a pump classification whose applications arebased upon transporting fluids from submersible elevations towards a fixed pipeline. Specific ESP pumps areutilized in offshore oil and gas facilities that are frequently employed in transport of Liquefied Natural Gas(LNG) terminals. Transport of LNG is a multiphase process that causes operational challenges for ESP due topresence of air pockets and air bubbles; presenting difficulties, such as cavitation and degradation to pumpcomponents. This performance degradation causes an economic risk to companies as well as a risk to pumpperformance capabilities, as it will not be able to pump with the same pressure again. Operational references formultiphase flow in ESP are limited; thus, this research paper reports multistage pumping, review offundamentals, previous experimental as well as modelling work benefitting future literature for a potentialsolution. Industries consume power to cope up with the losses associated with pumping two-phase fluidscausing company’s fortune. Preceding experimental work on single along with multiphase flow illustrate adistinct flow pattern surrounding the area around pump impeller while the pump is in operation. Throughexperimental observation, four flow patterns were observed and studied when gas was varied at different flowrates. Increasing the intake pressure proved to increase pump performance at two-phase flow. Experimentalstudy of multiphase flow with LNG fluid is expensive; thus, experimental validation is accomplished on asingle stage pump with external intervention of air bubbles to simulate LNG vaporization at fixed pressure andtemperature difference.

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Chapin, V. G., S. Jamme, and P. Chassaing. "Viscous Computational Fluid Dynamics as a Relevant Decision-Making Tool for Mast-Sail Aerodynamics." Marine Technology and SNAME News 42, no. 01 (January 1, 2005): 1–10. http://dx.doi.org/10.5957/mt1.2005.42.1.1.

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Viscous computational fluid dynamics based on Reynolds averaged Navier-Stokes (RANS) equations have been used to simulate flow around typical mast-sail geometries. It is shown how these advanced numerical methods are relevant to investigate the complexity of such strongly separated flows. Detailed numerical results have been obtained and compared to experimental ones. Comparative analysis has shown that RANS methods are able to capture the main flow features, such as mast-flow separation, recirculation bubble, bubble reattachment through a laminar-turbulent transition process, and trailing-edge separation. A second part has been devoted to the comparative behavior of these flow features through parameters variations to evaluate the qualitative and quantitative capabilities of RANS methods in mast-sail design optimization. The last part illustrates through two examples how RANS methods may be used to optimize the design of mast-sail geometries and evaluate their relative performances.

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Zangeneh, M., A. Goto, and H. Harada. "On the role of three-dimensional inverse design methods in turbomachinery shape optimization." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 213, no. 1 (January 1, 1999): 27–42. http://dx.doi.org/10.1243/0954406991522167.

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The application of a three-dimensional (3D) inverse design method in which the blade geometry is computed for a specified distribution of circulation to the design of turbomachinery blades is explored by using two examples. In the first instance the method is applied to the design of radial and mixed flow impellers to suppress secondary flows. Based on our understanding of the fluid dynamics of the flow in the impeller, simple guidelines are developed for input specification of the inverse method in order to systematically design impellers with suppressed secondary flows and a more uniform exit flow field. In the second example the method is applied to the design of a vaned diffuser. Again based on the understanding of the detailed flow field in the diffuser obtained by using 3D viscous calculations and oil flow visualizations, simple design guidelines are developed for input specification to the inverse method in order to suppress corner separation. In both cases the guidelines are verified numerically and in the case of the diffuser further experimental validation is presented.

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Vachagina, Ekaterina, Nikolay Dushin, Elvira Kutuzova, and Aidar Kadyirov. "Exact Solution for Viscoelastic Flow in Pipe and Experimental Validation." Polymers 14, no. 2 (January 15, 2022): 334. http://dx.doi.org/10.3390/polym14020334.

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The development of analytical methods for viscoelastic fluid flows is challenging. Currently, this problem has been solved for particular cases of multimode differential rheological equations of media state (Giesekus, the exponential form of Phan-Tien-Tanner, eXtended Pom-Pom). We propose a parametric method that yields solutions without additional assumptions. The method is based on the parametric representation of the unknown velocity functions and the stress tensor components as a function of coordinate. Experimental flow visualization based on the SIV (smoke image velocimetry) method was carried out to confirm the obtained results. Compared to the Giesekus model, the experimental data are best predicted by the eXtended Pom-Pom model.

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Hsu, Y., and C. E. Brennen. "Fluid Flow Equations for Rotordynamic Flows in Seals and Leakage Paths." Journal of Fluids Engineering 124, no. 1 (October 15, 2001): 176–81. http://dx.doi.org/10.1115/1.1436093.

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Fluid-induced rotordynamic forces produced by the fluid in an annular seal or in the leakage passage surrounding the shroud of a pump or turbine, are known to contribute substantially to the potential excitation forces acting on the rotor. The present research explores some of the important features of the equations governing bulk-flow models of these flows. This in turn suggests methods which might be used to solve these bulk-flow equations in circumstances where the linearized solutions may not be accurate. This paper presents a numerical method for these equations and discusses comparison of the computed results with experimental measurements for annular seals and pump leakage paths.

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Takahashi, Mamoru, Koji Iwano, Yasuhiko Sakai, and Yasumasa Ito. "OS22-1 Simultaneous measurement of pressure And temperature gradient in a planar jet(Thermal Transport Measurements and Multiphase Flow,OS22 Experimental method in fluid mechanics,FLUID AND THERMODYNAMICS)." Abstracts of ATEM : International Conference on Advanced Technology in Experimental Mechanics : Asian Conference on Experimental Mechanics 2015.14 (2015): 265. http://dx.doi.org/10.1299/jsmeatem.2015.14.265.

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Filonovich, M. S., R. Azevedo, L. R. Rojas-Solórzano, and J. B. Leal. "Credibility analysis of computational fluid dynamic simulations for compound channel flow." Journal of Hydroinformatics 15, no. 3 (February 18, 2013): 926–38. http://dx.doi.org/10.2166/hydro.2013.187.

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In this paper, verification and validation of a turbulence closure model is performed for an experimental compound channel flow, where the velocity and turbulent fields were measured by a Laser Doppler Velocimeter (LDV). Detailed Explicit Algebraic Reynolds Stress Model (EARSM) simulations are reported. There are numerous methods and techniques available to evaluate the numerical uncertainty associated with grid resolution. The authors have adopted the Grid Convergence Index (GCI) approach. The velocity components, the turbulence kinetic energy (TKE), the dissipation rate and the Reynolds stresses were used as variables of interest. The GCI results present low values for the u velocity component, but higher values in what concerns the v velocity component and w velocity component (representing secondary flows) and for Reynolds stresses RSxy and RSyz. This indicates that the mean flow has converged but the turbulent field and secondary flows still depend on grid resolution. Based on GCI values distribution, the medium and fine meshes were further refined. In addition to GCI analysis, the authors have performed linear regression analysis for estimating the mesh quality in what concerns small value variables. Comparison of numerical and experimental results shows good agreement.

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De Chant, L. J. "A Perturbation Model for the Oscillatory Flow of a Bingham Plastic in Rigid and Periodically Displaced Tubes." Journal of Biomechanical Engineering 121, no. 5 (October 1, 1999): 502–4. http://dx.doi.org/10.1115/1.2835079.

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An approximate analytical model for the pulsatile flow of an ideal Bingham plastic fluid in both a rigid and a periodically displaced tube has been developed using regular perturbation methods. Relationships are derived for the velocity field and dimensionless flow rate. The solution compares adequately with available experimentally measured oscillatory non-Newtonian fluid flow data. These solutions provide useful analytical models supporting experimental and computation studies of arterial blood flow.

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Sheikh Suleimany, Jehan M. Fattah, Tara H. Aurahman, and Bruska S. Mamand. "Flow simulation over semicircular labyrinth weir using ANSYS -fluent." Tikrit Journal of Engineering Sciences 29, no. 1 (April 5, 2022): 83–98. http://dx.doi.org/10.25130/tjes.29.1.7.

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This study investigates the flow of a semicircular labyrinth weir in an open channel by experimental and numerical methods. The experiments were carried out in a channel with a length of 3.5m and width of 0.25m and 0.3m height under five different flow rates. Five different discharge values over the weir were used. In each experiment, flow rate and flow depth were measured. Numerical processes solved using mathematical equations of fluid flow through the computational fluid dynamics using ANSYS FLUENT code. The Volume of Fluid (VOF) model is designed for the case of water and air-immiscible faces. Standard k-epsilon turbulence models were tested. A mass balance result indicates that the maximum error between the inlet and outlet discharges of the main channel does not exceed 12% for discharge values of 4.31 L/sec. The results indicate that by increasing the discharge flow rate, the percentage of error decreased to 0.4% for discharge, 14.6 L/sec. The findings show that the free water surface profile obtained from the numerical model compared to experimental values complies well with the experimental results.

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Sheikh Suleimany, Jehan M. Fattah, Tara H. Aurahman, and Bruska S. Mamand. "Flow simulation over semicircular labyrinth weir using ANSYS -fluent." Tikrit Journal of Engineering Sciences 29, no. 1 (April 23, 2022): 59–74. http://dx.doi.org/10.25130/tjes.29.1.6.

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This study investigates the flow of a semicircular labyrinth weir in an open channel by experimental and numerical methods. The experiments were carried out in a channel with a length of 3.5m and width of 0.25m and 0.3m height under five different flow rates. Five different discharge values over the weir were used. In each experiment, flow rate and flow depth were measured. Numerical processes solved using mathematical equations of fluid flow through the computational fluid dynamics using ANSYS FLUENT code. The Volume of Fluid (VOF) model is designed for the case of water and air-immiscible faces. Standard k-epsilon turbulence models were tested. A mass balance result indicates that the maximum error between the inlet and outlet discharges of the main channel does not exceed 12% for discharge values of 4.31 L/sec. The results indicate that by increasing the discharge flow rate, the percentage of error decreased to 0.4% for discharge, 14.6 L/sec. The findings show that the free water surface profile obtained from the numerical model compared to experimental values complies well with the experimental results.

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45

Setiawan, Irwan, Nurrohman ., and Hablinur Al Kindi. "ANALISA PRESSURE DROP DENGAN PENAMBAHAN ZAT ADITIF CAIRAN COOLANT PADA PIPA SILINDER MENGGUNAKAN METODE EMPIRIS DAN METODE EKSPERIMEN." AME (Aplikasi Mekanika dan Energi): Jurnal Ilmiah Teknik Mesin 4, no. 1 (January 1, 2018): 1. http://dx.doi.org/10.32832/ame.v4i1.985.

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The flow of fluid through the pipe creates fluid friction with pipe walls causing pressure drop and fluid flow velocity affecting the use of energy to drain it. Pressure drop can be affected by several factors such as friction or friction factor, pipe length, pipe diameter and fluid velocity. In this research, it will analyze pressure drop on piping system based on friction, fluid flow characteristics, and fluid velocity. The analysis was done by using two methods, namely experimental method and empirical calculation method. The stages of this study consist of problem analysis, literature study, calibration, data retrieval, empirical data processing and experiments, validation, analysis of results and conclusions. Based on the results of empirical and experimental research, the lowest pressure drop in the experiment and empirical was the 12 LPM discharge copper pipe and the water coolant ratio is 0: 100. This means that the best material pipes used were copper pipes rather than steel and galvanized pipes. The results of the tests and experiments have been tested for validation. The validation value of empirical and experimental data measurement is 91%.

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Ruggles, Arthur E., Bi Yao Zhang, and Spero M. Peters. "Positron Emission Tomography (PET) for Flow Measurement." Advanced Materials Research 301-303 (July 2011): 1316–21. http://dx.doi.org/10.4028/www.scientific.net/amr.301-303.1316.

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Positron Emission Tomography (PET) produces a three dimensional spatial distribution of positron-electron annihilations within an image volume. Various positron emitters are available for use in aqueous, organic and liquid metal flows. Preliminary experiments at the University of Tennessee at Knoxville (UTK) injected small flows of PET tracer into a bulk water flow in a four rod bundle. The trajectory and diffusion of the tracer in the bulk flow were then mapped using a PET scanner. A spatial resolution of 1.4 mm is achieved with current preclinical Micro-PET imaging equipment resulting in 200 MB 3D activity fields. A time resolved 3-D spatial activity profile was also measured. The PET imaging method is especially well suited to complex geometries where traditional optical methods such as LDV and PIV are difficult to apply. PET methods are uniquely useful for imaging in opaque fluids, opaque pressure boundaries, and multiphase studies. Several commercial and shareware Computational Fluid Dynamics (CFD) codes are currently used for science and engineering analysis and design. These codes produce detailed three dimensional flow predictions. The models produced by these codes are often difficult to validate. The development of this experimental technique offers a modality for the comparison of CFD outcomes with experimental data. Developed data sets from PET can be used in verification and validation exercises of simulation outcomes.

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Barraclough, Veronika, Jan Cizek, Miroslav Strob, Jan Novosad, Jaroslav Pulec, and Petra Dancova. "Ultrasonic methods for determining flows and velocity fields." EPJ Web of Conferences 264 (2022): 01001. http://dx.doi.org/10.1051/epjconf/202226401001.

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This paper introduces research and development of a modern non-invasive device for determining flows and velocity fields. This device is based on the ultrasonic method. The measured fluid flow is surrounded by appropriate ultrasonic transmitters and receivers, which communicate with each other. A physical principle of this method consists in an interaction of sound waves with a flow, which generates a certain delay in sound waves transmission. The found quantity is thus time delay. The device is being designed as a flowmeter and with advanced and extended postprocessing as a tomograph, which reconstructs a 3D vector field for big volumes. This whole process requires the following: development of an appropriate design of the ultrasonic flowmeter and tomograph, testing the signal transfer and also various postprocessing methods on a measurement accuracy, building of a special verification experimental equipment and building of an electronic device as a control unit and data acquisition system.

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Borazjani, Iman, John Westerdale, Eileen M. McMahon, Prathish K. Rajaraman, Jeffrey J. Heys, and Marek Belohlavek. "Left Ventricular Flow Analysis: Recent Advances in Numerical Methods and Applications in Cardiac Ultrasound." Computational and Mathematical Methods in Medicine 2013 (2013): 1–11. http://dx.doi.org/10.1155/2013/395081.

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The left ventricle (LV) pumps oxygenated blood from the lungs to the rest of the body through systemic circulation. The efficiency of such a pumping function is dependent on blood flow within the LV chamber. It is therefore crucial to accurately characterize LV hemodynamics. Improved understanding of LV hemodynamics is expected to provide important clinical diagnostic and prognostic information. We review the recent advances in numerical and experimental methods for characterizing LV flows and focus on analysis of intraventricular flow fields by echocardiographic particle image velocimetry (echo-PIV), due to its potential for broad and practical utility. Future research directions to advance patient-specific LV simulations include development of methods capable of resolving heart valves, higher temporal resolution, automated generation of three-dimensional (3D) geometry, and incorporating actual flow measurements into the numerical solution of the 3D cardiovascular fluid dynamics.

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TABOR, G., O. YEO, P. YOUNG, and P. LAITY. "CFD SIMULATION OF FLOW THROUGH AN OPEN CELL FOAM." International Journal of Modern Physics C 19, no. 05 (May 2008): 703–15. http://dx.doi.org/10.1142/s0129183108012509.

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A sample of an open-celled plastic foam has been examined using a combination of experimental, microscopic and computational methods. The aim was to use image-based meshing techniques to generate for the first time geometrically faithful models of the microstructure of the foam, and to use Computational Fluid Dynamics (CFD) to compute flow properties and pressure drops across the sample. The microstructure of the foam was also investigated experimentally and using SEM to provide further information for the computational analysis. A comparison was made with existing experimental data on flows through foams, and the unit pressure drop was found to correlate with the flow speed in the appropriate manner.

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Biscarini, Chiara, Silvia Di Francesco, Fernando Nardi, and Piergiorgio Manciola. "Detailed Simulation of Complex Hydraulic Problems with Macroscopic and Mesoscopic Mathematical Methods." Mathematical Problems in Engineering 2013 (2013): 1–14. http://dx.doi.org/10.1155/2013/928309.

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The numerical simulation of fast-moving fronts originating from dam or levee breaches is a challenging task for small scale engineering projects. In this work, the use of fully three-dimensional Navier-Stokes (NS) equations and lattice Boltzmann method (LBM) is proposed for testing the validity of, respectively, macroscopic and mesoscopic mathematical models. Macroscopic simulations are performed employing an open-source computational fluid dynamics (CFD) code that solves the NS combined with the volume of fluid (VOF) multiphase method to represent free-surface flows. The mesoscopic model is a front-tracking experimental variant of the LBM. In the proposed LBM the air-gas interface is represented as a surface with zero thickness that handles the passage of the density field from the light to the dense phase and vice versa. A single set of LBM equations represents the liquid phase, while the free surface is characterized by an additional variable, the liquid volume fraction. Case studies show advantages and disadvantages of the proposed LBM and NS with specific regard to the computational efficiency and accuracy in dealing with the simulation of flows through complex geometries. In particular, the validation of the model application is developed by simulating the flow propagating through a synthetic urban setting and comparing results with analytical and experimental laboratory measurements.

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Journal articles on the topic 'Experimental methods in fluid flow'

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