Journal articles: 'Hydrodynamics and hydraulic engineering'

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Evdokimov, Sergey V., and Alla A. Orlova. "Ensuring reliable operation of the hydraulic unit through the laws of contact hydrodynamics." Urban construction and architecture 12, no. 2 (June 20, 2022): 29–33. http://dx.doi.org/10.17673/10.17673/vestnik.2022.02.05.

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The article discusses the basic laws of contact hydrodynamics, which studies complex phenomena occurring in the lubricating layer separating the elastically deformable surfaces of various parts, and thus solves the complex problem of hydrodynamics, elasticity theory, thermodynamics, rheology of lubricants and materials science. For a long time, contact hydrodynamics was considered a secondary direction in hydraulic engineering, however, the main aspects of contact hydrodynamics allow determining the thickness of the lubricating layer in the elastic metal-plastic segments of the hydraulic unit bearings, ensuring the reliability and durability of their operation. Thus, contact hydrodynamics allowed us to gain a positive experience of long-term operational tests of elastic metal-plastic segments in the supports of hydraulic units of the largest hydroelectric power plants. In addition, contact hydrodynamics solved the problem of transferring all hydraulic units of large hydroelectric power plants of the country from rigid babbit supports to elastic composite ones; and all newly built hydro generators should be equipped with elastic segments of a new design.

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Han, Hui Xian, Xiong Hua Guo, and Xian Li Cao. "Design and Analysis for Hydraulic Travel System of Container Stacker." Advanced Materials Research 168-170 (December 2010): 230–34. http://dx.doi.org/10.4028/www.scientific.net/amr.168-170.230.

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Work conditions and requirements of a container stacker are analyzed. Aiming at the disadvantages of hydrodynamic travel system of stacker, a design method for hydraulic chassis of a stacker is presented. With a practical example, its operation performances under the work conditions of stable travel in low-speed are analyzed. New method to design its travel drive system is presented, it contains the hydraulic system design and component selection. It is considered that the manufacture cost for special hydraulic chassis of a stacker is equal to or lower than that of a hydrodynamics chassis, so there is wide application prospect of it.

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Persson, J., N. L. G. Somes, and T. H. F. Wong. "Hydraulics Efficiency of Constructed Wetlands and Ponds." Water Science and Technology 40, no. 3 (August 1, 1999): 291–300. http://dx.doi.org/10.2166/wst.1999.0174.

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Constructed ponds and wetlands are widely used in urban design to serve a number of functions including stormwater management. The design of constructed wetlands for stormwater management involves a number of multi-disciplinary inputs. Fundamental to their sustainable operation are the proper control of the hydrologic regime of the wetland and optimal flow hydrodynamics within the wetland. Many ofthe problems encountered in constructed wetlands can be minimised or avoided by good engineering design principles. Poor wetland hydrodynamics are often identified as a major contributor to wetland management problems. Ponds and wetlands with a high hydraulic efficiency are expected to promote full utilisation ofthe available detention storage and near plug flow conditions. The shape and layout of urban ponds and wetlands are often varied to suit the landscape and to satisfy aesthetic requirements as an urban water feature. These can be achieved while maintaining an effective stormwater treatment outcome if steps are taken to ensure that the hydrodynamic behaviour of the system is not severely compromised. A consistent measure is required to allow the effects of design features to be evaluated against this criterion. This paper introduces a new measure for hydraulic efficiency that combines existing measures of flow uniformity and effective volume. Case studies are presented on the use of this measure to assess the effects of different pond and wetland shapes, locations of inlet and outlet, botanical layouts and basin morphology on the flow hydrodynamics.

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Wang, Haifei, Shimin Yang, and Tan Lu. "Performance-Matching Optimization Design of Loader-Hydraulic System Based on Hydrodynamics Analysis." Processes 10, no. 8 (August 3, 2022): 1524. http://dx.doi.org/10.3390/pr10081524.

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The study of the performance of dynamic hydraulic throttling under the condition of stable fluid is of great significance. The effect of a step change in pressure differences on the throttling performance of a hydraulic valve is studied. This paper studies the dynamic and static performance of a hydraulic-valve-outlet throttling-speed regulation system, builds a more accurate mathematical model, considers the linear factors of the flow of hydraulic-valve throttling, analyzes the influence of the step-load change in pressure difference on the stability of the hydraulic-valve movement speed, and constructs a nonlinear mathematical model of the speed-regulation system of the outlet throttling. A pressure sensor is used to measure the change in pressure overshoot, and the effect of a pressure-difference step change on the throttling performance of the hydraulic valve is studied under steady-fluid conditions. The theory is analyzed and verified by experiment, and the parameters of hydraulic components are modified using the dynamic-change rule of the hydraulic valve’s two-chamber pressure.

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Tang, Zhi Yin, Gang Wu, Jun Yong Lu, Yan Fei Li, and Xiang Li. "Application of Variable Damping Hydraulic Buffer in Braking Large Mass Impact Loading Problem." Applied Mechanics and Materials 716-717 (December 2014): 619–22. http://dx.doi.org/10.4028/www.scientific.net/amm.716-717.619.

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Aimed at braking large mass impact loading problem, a mathematical model of the multi-orifice hydraulic buffer has been established, with the use of hydrodynamics theory, hydraulic theory and engineering structural mechanics theory. Damping characteristic curves under different operating conditions have been analyzed. The problem that traditional hydraulic buffer damping characteristics could not match to different mass impact loading well has been found. By analyzing the influence of buffer cylinder structural parameters on buffer damping characteristics, a variable damping buffer has been proposed, and the problem has been verified with simulation.

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Passos, Ricardo Gomes, Marcos von Sperling, and Thiago Bressani Ribeiro. "Hydrodynamic evaluation of a full-scale facultative pond by computational fluid dynamics (CFD) and field measurements." Water Science and Technology 70, no. 3 (June 12, 2014): 569–75. http://dx.doi.org/10.2166/wst.2014.265.

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Knowledge of the hydraulic behaviour is very important in the characterization of a stabilization pond, since pond hydrodynamics plays a fundamental role in treatment efficiency. An advanced hydrodynamics characterization may be achieved by carrying out measurements with tracers, dyes and drogues or using mathematical simulation employing computational fluid dynamics (CFD). The current study involved experimental determinations and mathematical simulations of a full-scale facultative pond in Brazil. A 3D CFD model showed major flow lines, degree of dispersion, dead zones and short circuit regions in the pond. Drogue tracking, wind measurements and dye dispersion were also used in order to obtain information about the actual flow in the pond and as a means of assessing the performance of the CFD model. The drogue, designed and built as part of this research, and which included a geographical positioning system (GPS), presented very satisfactory results. The CFD modelling has proven to be very useful in the evaluation of the hydrodynamic conditions of the facultative pond. A virtual tracer test allowed an estimation of the real mean hydraulic retention time and mixing conditions in the pond. The computational model in CFD corresponded well to what was verified in the field.

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LÓPEZ, DAVID. "Smoothed particle hydrodynamics model applied to hydraulic structures: a hydraulic jump test case." Journal of Hydraulic Research 48, extra (2009): 000. http://dx.doi.org/10.3826/jhr.2010.0015.

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López, David, Roberto Marivela, and Luis Garrote. "Smoothed particle hydrodynamics model applied to hydraulic structures: a hydraulic jump test case." Journal of Hydraulic Research 48, sup1 (January 1, 2010): 142–58. http://dx.doi.org/10.1080/00221686.2010.9641255.

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Zhu, Di, Ruofu Xiao, Ran Tao, and Weichao Liu. "Impact of guide vane opening angle on the flow stability in a pump-turbine in pump mode." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 231, no. 13 (March 3, 2016): 2484–92. http://dx.doi.org/10.1177/0954406216635204.

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In the pump mode (storage mode) of a pump-turbine, unstable head variations occur as the flow rate decreases, leading to unstable, unsafe operation. Thus, the hydrodynamics of pump-turbines in the unstable operating range should be investigated to improve their designs. This study presents experimental and numerical studies of the hydrodynamics. The experiments investigated the external characteristics with the head instabilities captured by both the model tests and the computational fluid dynamics simulations. The computational fluid dynamics model used detached eddy simulations to study the flow details which showed that hydraulic losses were the reason for the unstable head variations and the poor flow regime was the source of the losses. In the unstable, low flow rate range, the flow direction is no longer consistent with the guide vane direction, so undesirable flow structures develop in the passages. Therefore, appropriate guide vane opening angles are needed to improve the flow regime and reduce the hydraulic losses. These will enhance the operating stability and safety in engineering applications.

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Fadl-Elmola, Salman A. M., Cristian Moisescu Ciocan, and Ioana Popescu. "Application of Smooth Particle Hydrodynamics to Particular Flow Cases Solved by Saint-Venant Equations." Water 13, no. 12 (June 16, 2021): 1671. http://dx.doi.org/10.3390/w13121671.

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Smoothed particle hydrodynamics (SPH) is a Lagrangian mesh free particle method which has been developed and widely applied to different areas in engineering. Recently, the SPH method has also been used to solve the shallow water equations, resulting in (SPH-SWEs) formulations. With the significant developments made, SPH-SWEs provide an accurate computational tool for solving problems of wave propagation, flood inundation, and wet-dry interfaces. Capabilities of the SPH method to solve Saint-Venant equations have been tested using a SPH-SWE code to simulate different hydraulic test cases. Results were compared to other established and commercial hydraulic modelling packages that use Eulerian approaches. The test cases cover non-uniform steady state profiles, wave propagation, and flood inundation cases. The SPH-SWEs simulations provided results that compared well with other established and commercial hydraulic modeling packages. Nevertheless, SPH-SWEs simulations experienced some drawbacks such as loss of inflow water volume of up to 2%, for 2D flood propagation. Simulations were carried out using an open source solver, named SWE-SPHysics.

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A. A., Yuldashov, and Karimov G. X. "Models of Distribution of Flow Parameters in Intensive Garden Irrigation, System Pipes." International Journal for Research in Applied Science and Engineering Technology 10, no. 3 (March 31, 2022): 838–44. http://dx.doi.org/10.22214/ijraset.2022.40692.

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Annotation: The mathematical description of the movement of water in the systems of irrigation pipelines, based on the equation of continuity of the medium, the system of Navy-Stokes equations. The resulting mathematical package describes a system with distributed parameters and is performed based on the condition of dynamic balance at the point of flow, taking into account the dependence on the nature of the flow and the physical properties of the environment. Calculation is executed with use of functions Besseliya. Methodology for calculating the hydrodynamic component of water movement in irrigation water supply systems. Pipelines are universal in nature and can be used in the calculation, construction and assessment of the stability of water supply hydraulic systems; the technique can be used to describe the object of operation in the construction of control systems for the hydraulic parameters of the water supply system. Keywords: pipeline, irrigation systems, non-uniformity, liquid, water, strength, function, three-dimensional, water supply, hydrodynamics, hydrostatics, quasi-one-dimensional, unsteady, flow, potential, surface, coordinate system, stresses, projection, velocity, cylindrical coordinates, unsteady motion , asymmetric, viscous, compressible fluid, plastic pipe

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Shcherbakov, Alexey, and Valentin Zhezmer. "Brief history and ways of further development of the department of hydraulic engineering and hydraulics FSBI «VNIIGiM named after A.N. Kostyakov»." Melioration and Water Management, no. 5 (February 6, 2020): 18–23. http://dx.doi.org/10.32962/0235-2524-2019-5-18-23.

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Department of hydraulic engineering and hydraulics FGBNU «VNIIGiM them. A.N. Kostyakova «has a long history. For many years, the department’s staff has been such scientists and water engineers with extensive experience as M.A. Volynov, V.S. Verbitsky, S.S. Medvedev, N.V. Lebedev, B.C. Panfilov, T.G. Voynich-Syanozhentsky, V.A. Golubkova, G.V. Lyapin and others. The department solved a wide range of tasks, the main areas of research were the following: – theoretical and applied hydrodynamics and hydraulics, with reference to the open channel flows that affect the state and level of safety of the hydraulic structures; – integrated use and protection of water bodies – water sources and water sources of water resources used in land reclamation; – development of measures and technical solutions for the protection of objects from the negative effects of water; – theoretical substantiation of works to improve the safety level of the GTS (declaration); – development and implementation of digitalization methods for solving design, construction, operation and control of landreclamation facilities. Currently, promising areas of research is the development of a decision-making algorithm in the designation of measures to rationalize the provision of resources to water amelioration. The algorithm is developed on the basis of a detailed study, systematization and processing of data both on safety and on the efficiency of systems and structures, ensuring the delivery of irrigation water of the required quality and in sufficient quantity from a water source to the field.

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Pinheiro, Antonio Gebson, Alexandre Maniçoba Da Rosa Ferraz Jardim, Abelardo Antônio De Assunção Montenegro, Thieres George Freire da Silva, and José Raliuson Inácio Silva. "Characterization of alluvial soil hydrodynamics in the upper Ipanema river basin using the Beerkan method." DYNA 88, no. 218 (September 5, 2021): 178–84. http://dx.doi.org/10.15446/dyna.v88n218.91077.

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The objective was to model the spatial distribution of the physical properties of the soil through geostatistics in the Brazilian semi-arid region. The study was carried out in the Experimental Basin of Ipanema River, Pernambuco, in an alluvial area with regular grid and samples of 40 points. Infiltration tests were carried out to assess hydraulic conductivity and sampling was performed to determine soil texture and soil organic carbon (SOC). The variables were subjected to descriptive and correlation statistical analyses, in addition to the geostatistical report, which indicated high variability for the hydraulic conductivity of the soil. The best fits were obtained with the Spherical model for the hydraulic conductivity, sand, silt, and clay variables, and the Gaussian model for SOC. Thus, with the geostatistics technique, it was possible to map and verify the main physical characteristics of the soil in the area, providing greater optimization in agriculturalplanning

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Kang, Jia-Lin, Siao-Han Huang, and Shi-Shang Jang. "Evaluation of Hydrodynamic Performance of New Random Packing Structure Using CFD." Processes 10, no. 7 (June 29, 2022): 1276. http://dx.doi.org/10.3390/pr10071276.

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This study demonstrates the use of computational fluid dynamics (CFD) to evaluate the hydraulic properties of a new/complicated random packing structure, including flooding point, interfacial area, and liquid holdup. A standard Raschig ring and an extremely complex helical ring were employed as representative traditional and new structures. The combination of Green-Gauss node-based method with polyhedral meshing was presented to improve the hydraulic predictions. The CFD models were adopted to extend the liquid-to-gas ratio, L/G to the flooding points for hydraulic evaluation. The combination to calculate the gradient is essential for correctly evaluating the hydrodynamics of the complex helical ring. The predicted hydrodynamics for the helical ring were in good agreement with the experimental data. The helical ring has a wider operating range of L/G than the Raschig ring. Furthermore, we observed that the gas-liquid interface changed during the flooding and found that the inverted interfacial area was caused due to the flooding affecting the generation of the gas-liquid interface. The hydrodynamics of the Raschig ring and helical ring were compared based on CFD simulations; notably, the helical ring exhibited a wider range of L/G ratios and a better hydraulic performance. Finally, the flooding behaviors of the Raschig ring and the helical ring were investigated through volume fraction contours in CFD. We found that a part of the liquid was blown away, leading to the gas-liquid mixing area increasing at the flooding point. A severe flooding state can be investigated due to a large volume of liquid leaving the upper outlet which could be found when over the flooding point.

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Lade, Abhijit D., Jyotismita Taye, and Bimlesh Kumar. "Effect of sand mining on the flow hydrodynamics around an oblong bridge pier." Engineering Research Express 3, no. 4 (November 22, 2021): 045028. http://dx.doi.org/10.1088/2631-8695/ac396e.

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Abstract Extraction of sand from riverbed has catastrophic repercussions on aquatic animalia habitat, water quality, and the environment. Alongside, physical alterations in the fluvial hydraulics arising on account of sand mining are also worthy of attention. Flows passing over the pits excavated in a channel have enhanced erosive propensity, which can be a cause of concern for the downstream hydraulic structures. The complex nature of flow interacting with the bridge piers after passing over a mining pit is not fully understood. Experiments were conducted to apprehend the effects of a dredged pit on the turbulence flow-field around an oblong pier. Flow was passed in an erodible sand bed rectangular channel having an oblong pier for the first case. In the second case, a pit was dredged in the mobile bed to replicate a mined channel, and the pier was subjected to the same discharge. The streambed at the approach of the pier experiences greater mean bed shear because of dredging. The amplification of the instantaneous bed shear beneath the turbulent horseshoe vortex (THSV) zone at the pier front is almost twice due to channel dredging. The findings can be useful in understanding the streambed instabilities around bridge piers in mining-infested channels.

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Majtan, Eda, Lee S. Cunningham, and Benedict D. Rogers. "Experimental and Numerical Investigation of Floating Large Woody Debris Impact on a Masonry Arch Bridge." Journal of Marine Science and Engineering 10, no. 7 (July 1, 2022): 911. http://dx.doi.org/10.3390/jmse10070911.

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Masonry arch bridges form an essential part of existing transport infrastructure around the world, including mainland Europe and the northeastern US. Recent extreme flood events highlight that masonry arch bridges spanning watercourses are vulnerable to flood-induced hydrodynamic and debris impact loads. When the flow interacts with the bridge superstructure, with or without discrete floating debris, a complex interaction is observed. This paper presents both experimental and numerical studies to investigate this complex phenomenon, including fluid–structure and structure–structure interactions. A typical single-span masonry arch bridge and large woody debris representing a tree log are investigated. Experimental observations from a scaled hydraulic model, with and without debris in the flow, are first presented for the case where the abutment of the bridge is fully submerged. Next, the capability of the numerical method smoothed particle hydrodynamics (SPH) in simulating the hydrodynamic behaviour and debris impact observed in the experiment is discussed. Following this, both hydrodynamic and debris-induced pressure–time histories on the bridge are obtained using the SPH model. Results reveal that the debris impact leads to a significantly more localised load on the bridge compared to the situation with hydrodynamic load only.

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Alba, Javier García, Aina G. Gómez, Pilar del Barrio Fernández, Andrés García Gómez, and César Álvarez Díaz. "Hydrodynamic modelling of a regulated Mediterranean coastal lagoon, the Albufera of Valencia (Spain)." Journal of Hydroinformatics 16, no. 5 (February 22, 2014): 1062–76. http://dx.doi.org/10.2166/hydro.2014.071.

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Coastal lagoon hydrodynamics are strongly influenced by sea water exchange, especially when the connection between the lagoon and the sea is artificially regulated. These situations increase the complexity of the hydrodynamic regime, requiring the use of numerical models to understand their behaviour. Traditionally, one-dimensional models have been used, although in recent years, the development of two-dimensional shallow water models and advanced numerical techniques have increased notably. However, most of the existing bi-dimensional models consider the connection to the sea as a boundary condition, and they do not take into consideration the sea-lagoon exchange. In this paper, a fully two-dimensional hydrodynamic model of a heavily regulated coastal lagoon, which includes the artificial connection with the sea, is presented. The model allows the characterization of water level variation in the lagoon, taking into account the combined effect of different forcings. This model consists of two hydrodynamic modules: a long wave module (two-dimensional depth-averaged) which includes the analysis of a system of sluice gates, and a wind module (quasi three-dimensional). The model was successfully calibrated and validated with real data, showing its ability to accurately describe the hydraulic dynamics of regulated coastal lagoons.

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Robert, Jean-Loup, and Mohammad Hossein Hamedi. "Introduction des conditions réelles de débit aux limites d'un modèle hydrodynamique." Canadian Journal of Civil Engineering 22, no. 6 (December 1, 1995): 1133–42. http://dx.doi.org/10.1139/l95-131.

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The main goal of this paper is to present a technique to improve the specification of discharge at the open boundaries of a hydrodynamic numerical model. Generally, two dimensional models need boundary conditions using imposed values of water level and (or) velocity components. Although these conditions are satisfactory in most situations, they are not sufficient for open channel flow modelling, in which the discharge is set up according to the upstream hydraulic head. The integral form, needed by finite element modelling, is useful to generate explicit boundary terms that, adequately used, allow the introduction of discharge boundary conditions at open borders of the application domain. The theoretical aspects of this approach are first detailed and, to check the validity of the development and to evaluate the reliability of the model as a design tool, the numerical results are compared with observations on an experimental installation. The results allow to conclude that the proposed model offer a wide range of applications and a high level of accuracy and that it can be considered as a useful aid for hydraulic design. Key words: hydrodynamics, free surface flow, modelling, finite elements, discharge law, boundary conditions, numerical-experimental comparison.

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Abid, Mohammad F., Zainab Y. Shanain, and Kadhim N. Abed. "Experimental and analysis study on dispersion of phases in an Ebullated Bed Reactor." Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles 74 (2019): 20. http://dx.doi.org/10.2516/ogst/2018103.

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The effectiveness and performance of industrial hydro-processing Ebullated Bed Reactors (EBRs) are highly dependent on the bed hydrodynamics and operating conditions. In present work, hydrodynamics of EBRs was studied in a cold model experimental setup using air–water–solid particles system. Pressure gradient method and Residence Time Distribution (RTD) technique were used to estimate the individual holdups, and dispersion coefficients in the lab-scale ebullated bed column. System Hydraulic Efficiency (HEF) was also estimated. The results showed that liquid internal recycle ratio, which characterized the EBRs, has a predominant effect on the individual holdups and dispersion coefficients. Empirical correlations were developed for prediction of phase holdups, and dispersion coefficients with good accuracy.

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Khosronejad, Ali, and C. D. Rennie. "Three-dimensional numerical modeling of unconfined and confined wall-jet flow with two different turbulence models." Canadian Journal of Civil Engineering 37, no. 4 (April 2010): 576–87. http://dx.doi.org/10.1139/l09-172.

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Wall-jet flow is an important flow field in hydraulic engineering, and its applications include flow from the bottom outlet of dams and sluice gates. An in-house three-dimensional (3-D) finite-volume Reynolds-averaged-Navier-Stokes (RANS) numerical model predicts the hydrodynamic characteristics of wall jets with square and rectangular source geometry. Either the low-turbulence Reynolds number k–ω or the standard k–ε turbulence closure models are applied. The calculated results for velocity profile and bed shear stress in both longitudinal and vertical directions compare favourably with both the published experimental results and the FLUENT® finite volume model. The two closure models are compared with the k–ω model, displaying 4% greater average accuracy than the k–ε model. Finally, the influence of lateral confinement of the receiving channel on wall-jet hydrodynamics is investigated, with decreased longitudinal deceleration and decreased bed shear stress observed in a confined jet. This has important implications for sediment transport in the receiving channels downstream of sluice gates.

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Ibrahimov, Rafiq, Shirin Bahshaliyeva, and Zaur Ibrahimov. "Analysis of the hydraulic characteristics of flushing fluid when gas enters wells drilled from semi-submersible drilling rigs." Nafta-Gaz 78, no. 6 (June 2022): 422–25. http://dx.doi.org/10.18668/ng.2022.06.02.

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The article considers how in recent years the study of hydraulics and hydrodynamics have been successfully used in the qualitative analysis of complications arising during the drilling of wells. One of the main factors determining the success of well drilling is hydrodynamic pressure. Also a boundary layer forms both on the wall of the casings and on the walls of the well has important means. One potential complication is the appearance of gas when a well is drilled from a semi-submersible drilling rig. The article deals with issues of clarifying the nature and eliminating gas, as well as preventive measures and their consequences. However, in order to take a final decision it is necessary to analyse the nature of the pressure change at the blowout preventer on a semi-submersible drilling rig. A number of works have been devoted to determining hydraulic pressure and hydraulic resistance in the circulation system of wells, on the basis of both stationary and non-stationary processes. Gas was observed in well no. 28 of the Sangachal-Sea field (Caspian Sea, Azerbaijan) at a depth of 3819 m and with a specific gravity of the flushing fluid of 2.25–2.27 g/cm3. When the blowout preventer was closed, the pressure increased to 10 MPa for 2–3 hours, before decreasing to 2.5 MPa and stabilising. The conclusion from this is that if the flow rate, the angle of deviation of the installation and contact time of the surfaces are constant, the influence of the flushing fluid decreases as the pressure drop increases. As the fluid filtration rate increases, the friction force between the drill pipe and the borehole wall increases. The friction force between the surfaces of the column and the filter cake is inversely proportional to the fillet velocity.

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Suri, Yatin, Sheikh Zahidul Islam, and Mamdud Hossain. "Effect of fracture roughness on the hydrodynamics of proppant transport in hydraulic fractures." Journal of Natural Gas Science and Engineering 80 (August 2020): 103401. http://dx.doi.org/10.1016/j.jngse.2020.103401.

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Yu, Shuyang, Xuhua Ren, Haijun Wang, Jixun Zhang, and Zhaohua Sun. "Numerical Analysis of the Hydraulic Fracturing of Pressure Tunnel Lining Based on the 2P-IKSPH Method." Mathematical Problems in Engineering 2021 (June 15, 2021): 1–13. http://dx.doi.org/10.1155/2021/5583822.

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In order to investigate the fracture mechanisms of the pressure tunnel lining under water-stress coupling, based on the traditional smoothed particle hydrodynamics (SPH) method, the solid-water particle interaction method, and the particle damage conversion algorithm are proposed to realize the hydraulic fracturing process, which is called the 2P-IKSPH method. The “particle domain searching method,” the “birth-and-death particle method,” and the “group discrimination searching method” have also been proposed to realize the simulations of complex processes of excavation, lining, and operation of the hydraulic tunnel. Taking the Guzeng hydraulic tunnel as an engineering example, the hydraulic fracturing of tunnel lining under different conditions is numerically simulated. Results show the following: (1) the 2P-IKSPH method can dynamically reflect the stress wave propagation processes of surrounding rock and the damage process of tunnel lining. (2) The lining damage mainly occurs on the vault and the arch foot. (3) The critical internal water pressure increases with the increase of the tunnel buried depth and the thickness of lining, but increases first and then decreases with the increase of the surrounding rock mass grade. The research results can provide some references for the optimization designs of tunnel lining and reinforcement of similar projects. Meanwhile, developing 3D parallelization program based on 2P-IKSPH will be the future research directions.

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Dai, Zili, Yu Huang, and Qiang Xu. "A hydraulic soil erosion model based on a weakly compressible smoothed particle hydrodynamics method." Bulletin of Engineering Geology and the Environment 78, no. 8 (March 14, 2019): 5853–64. http://dx.doi.org/10.1007/s10064-019-01489-z.

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Todić, Nenad, Slobodan Savić, Dušan Gordić, and Radovan Petrović. "Experimental Research of the Hydrodynamic Processes of an Axial Piston Water Hydraulic Pump." Machines 10, no. 9 (August 26, 2022): 728. http://dx.doi.org/10.3390/machines10090728.

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Water hydraulic components and systems play pivotal roles in the development of modern hydraulics. Sustainable development and environmental protection cannot be imagined without the use of water as a working medium in modern hydraulic systems. An axial piston pump is the main component of these systems. This paper presents analytical and experimental methods for the development of an axial piston pump. The presented mathematical model is rooted in numerous research results in the literature and in our own experience. It is based on mathematical modelling of hydrodynamic processes of a water hydraulic axial piston pump which, combined with experimental research, provides a great tool to analyse the influence of different factors on the operating process and to optimise the pump parameters. The experimental equipment used in our tests simulates a real hydraulic installation, and the obtained results are very close to the actual operating parameters. This research included a modification of the swash plate in order to achieve ideal operating parameters and, thus, extend the service life of the pump. Water has a number of advantages over conventional hydraulic oils. It is a sustainable, environmentally friendly resource, more readily available than oil (lower transportation costs), cheaper to dispose of, non-flammable and non-toxic, and its high thermal conductivity aids in cooling.

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Syamsuri, Ming-Jyh Chern, and Nima Vaziri. "Effect of Porous Media on Hydraulic Jump Characteristics by Using Smooth Particle Hydrodynamics Method." International Journal of Civil Engineering 18, no. 3 (October 23, 2019): 367–79. http://dx.doi.org/10.1007/s40999-019-00465-8.

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Phiri, Z., Y. Saito, Bakri Bin Ishak, H. Harada, and S. Nakajima. "Optimization of the performance of hoppered peripheral-feed clarifiers." Water Science and Technology 33, no. 8 (April 1, 1996): 125–33. http://dx.doi.org/10.2166/wst.1996.0159.

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The tide of “development” gathering pace in developing countries has resulted in the production of increasing quantities of wastewaters. This inevitably necessitates a reappraisal/reassessment of wastewater technologies. This study demonstrates the role of simple physical modelling approaches in evaluating/appraising the technical performance of hoppered peripheral-feed (spiral-flow) clarifiers -- which clarifiers have enormous scope for use in small plants in developing countries. The study focuses on the optimization of local geometrics and hydrodynamics for the purposes of improving overall performance in hoppered spiral flow clarifiers. It is concluded that for a defined set of clarifier global geometry and loading conditions, an optimum race width and inlet nozzle diameter exist. The optimum values of these parameters for a defined conceptual prototype are presented. It is further concluded that the mere variation of either the race width or the inlet nozzle diameter significantly affects the hydraulic detention and solids removal interrelationships in hoppered spiral flow clarifiers. Under the conditions of this study, a 50% reduction in inlet nozzle diameter resulted in an incredible more than 50% loss in hydraulic efficiency. Overall, the possibility of significantly increasing clarifier capacity and/or overall performance by simply optimizing local geometrics and hydrodynamics has been demonstrated via a well tested and friendly methodology.

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Yang, Chih Ted. "Variational Theories in Hydrodynamics and Hydraulics." Journal of Hydraulic Engineering 120, no. 6 (June 1994): 737–56. http://dx.doi.org/10.1061/(asce)0733-9429(1994)120:6(737).

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29

Bonnet, Benjamin, Denis Dochain, and Jean-Philippe Steyer. "Dynamical modelling of an anaerobic digestion fluidized bed reactor." Water Science and Technology 36, no. 5 (September 1, 1997): 285–92. http://dx.doi.org/10.2166/wst.1997.0218.

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One of the main difficulties in modelling a Fluidized Bed Biofilm Reactor (FBBR) is to take into account hydraulic phenomena (such as bed expansion) and its interactions with the biological variables. In this paper, we shall present a dynamical model of the process, analyse the stability of the hydrodynamics and illustrate its performances in simulation. A key feature of the model is that it combines mass balance of the process components with momentum balance equations in order to emphasise the different hydrodynamics of the liquid phase and of the solid phase, and the interactions between both phases. The model derivation finally leads to a set of partial differential equations (PDE). This model is intended to be used as a basis for the derivation of controllers and for dynamical simulation.

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30

Bogdevicius, Marijonas, Vigaile Semaskaite, Tatjana Paulauskiene, Jochen Uebe, and Algimantas Danilevicius. "Modelling and Simulation Hydrodynamics Processes in Liquefied Natural Gas Transportation Systems." Journal of Marine Science and Engineering 10, no. 12 (December 9, 2022): 1960. http://dx.doi.org/10.3390/jmse10121960.

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Global natural gas resources are growing and are increasingly geographically diverse. A Floating Storage and Regasification Unit (FSRU) is one of the most commonly used vessel types in the global ship fleet due to the possibility of storage, reloading to another ship, and regasifying it for re-injection into the natural gas grid. It is important to control system parameters for reliable technological processes such as tank hydrostatic pressure, vapor pressure, LNG density, LNG temperature, and phase changes between liquid and gas states. Additionally, pressure monitoring is important to control during transit in port and bunkering to prevent the pressure in the tanks from exceeding the tank design pressure. In this research study, a comprehensive hydrodynamic model for an LNG storage tank in a real-life regasification terminal (Floating Storage and Regasification Unit, LNG Terminal of Klaipeda City, Lithuania), operating in transportation mode to the regasification unit, was created. For this research, LNG is investigated as a compressible liquid and the speed of sound in LNG is evaluated. A complex mathematical model of the system allows the analysis of high-speed hydrodynamic and dynamic processes at cryogenic temperature (110 K) and evaluates the geometric parameters (tank geometry, electric motors and pumps, pipe geometric parameters, and roughness of internal surfaces) and the characteristics of pumps and electric motors. The complex mathematical model of the system was implemented using Fortran programing language and MATLAB R28a. It determined the parameters (pressure, velocity, liquid level of LNG in the tanks, electric motor angular velocity, torques, hydraulic energy losses, etc.) of the system during its start-up mode (until 5 s). It was found that hydraulic energy losses in all pipes contain 1.7% of the whole system power (the total power of the electric motors is 3132 kW). In case of increasing energy costs, this model could be used to control energy losses during the operation of the FSRU in various technological modes.

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Gidas, Nicolas K., and Vladimir G. Koutitonsky. "Simulations expérimentale et numérique de la dispersion hydrodynamique d'un effluent pollué en milieu côtier estuarien." Canadian Journal of Civil Engineering 23, no. 4 (August 1, 1996): 820–37. http://dx.doi.org/10.1139/l96-891.

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An experimental and numerical study was performed to measure and simulate the hydrodynamic dispersion of a pollutant effluent discharged by an outfall diffuser into an estuarine coastal zone near Rimouski, Canada. Field measurements of currents, tides, salinity, and winds were obtained in the vicinity of the injection site, and two tracer dispersion experiments were carried on in these coastal waters. The measurements were taken before and after the construction of the marine outfall diffuser. The similitude between the plume of a tracer (physical model) released into the coastal waters before construction and that of the real effluent (prototype) discharged at the same site was studied. A new coefficient of similitude was established, which allows to transpose the concentrations of the physical model tracer to the waste water concentrations of the prototype. The numerical simulation (2D) is performed with a hydrodynamic model and an advection–dispersion model of the MIKE21 system from the Danish Hydraulic Institute, using the so-called telescopic approach. The objective of these simulations was to predict, among other things, the pollutant effluent concentrations for critical hydrodynamic conditions relative to the aquatic ecosystem to be protected. The methodology elaborated was used for the management of the coastal environments subjected to pollution. Key words: simulation, hydrodynamics, advection–dispersion, numerical model, similitude, tide, effluent.

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32

Belozerov, Vladimir I., and Aleksandr S. Gorbach. "Investigation of the critical heat flux in small-diameter channels." Nuclear Energy and Technology 7, no. 1 (March 30, 2021): 73–78. http://dx.doi.org/10.3897/nucet.7.65754.

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The paper describes experimental studies into the hydrodynamics and heat exchange in a forced water flow in small-diameter channels at low pressures. The timeliness of the studies has been defined by the growing interest in small-size heat exchangers. Small-diameter channels are actively used in components of compact heat exchangers for present-day engineering development applications. The major difficulty involved in investigation of heat-transfer processes in small-diameter channels consists in the absence of common methodologies to calculate coefficients of hydraulic resistance and heat transfer in a two-phase flow. The channel size influences the heat exchange and hydrodynamics of a two-phase flow as one of the determining parameters since the existing internal scales (vapor bubble size, liquid droplet diameter, film thickness) may become commensurable with the channel diameter, this leading potentially to different flow conditions. It is evident that one cannot justifiably expect a change in the momentum and energy transfer regularities in single-phase flows as the channel size is reduced for as long as the continuum approximation remains valid. The authors have analyzed the experiments undertaken by Russian scientists to investigate the distribution of thermal-hydraulic parameters in channels with a small cross-section in the entire variation range of the flow parameters in the channel up to the critical heat flux conditions when the wall temperature increases sharply as the thermal load grows slowly. The experimental critical heat flux data obtained by Russian and foreign authors has been compared.

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Plewik, Roch, Piotr Synowiec, and Janusz Wójcik. "Two-phase CFD simulation of the monodyspersed suspension hydraulic behaviour in the tank apparatus from a circulatory pipe." Polish Journal of Chemical Technology 10, no. 1 (January 1, 2008): 22–27. http://dx.doi.org/10.2478/v10026-008-0006-6.

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Two-phase CFD simulation of the monodyspersed suspension hydraulic behaviour in the tank apparatus from a circulatory pipe The hydrodynamics in fluidized-bed crystallizers is studied by CFD method. The simulations were performed by a commercial packet of computational fluid dynamics Fluent 6.x. For the one-phase modelling (15), a standard k-ε model was applied. In the case of the two-phase flows the Eulerian multi-phase model with a standard k-ε method, aided by the k-ε dispersed model for viscosity, has been used respectively. The collected data put a new light on the suspension flow behaviour in the annular zone of the fluidised bed crystallizer. From the presented here CFD simulations, it clearly issues that the real hydraulic conditions in the fluidised bed crystallizers are far from the ideal ones.

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Vieira, Isabela De Luna, Jhonatan Barbosa Da Silva, Carlos Nobuyoshi Ide, and Johannes Gérson Janzen. "Effects of scale and Froude number on the hydraulics of waste stabilization ponds." Water Science and Technology 77, no. 1 (October 23, 2017): 239–47. http://dx.doi.org/10.2166/wst.2017.529.

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Abstract This paper presents the findings from a series of computational fluid dynamics simulations to estimate the effect of scale and Froude number on hydraulic performance and effluent pollutant fraction of scaled waste stabilization ponds designed using Froude similarity. Prior to its application, the model was verified by comparing the computational and experimental results of a model scaled pond, showing good agreement and confirming that the model accurately reproduces the hydrodynamics and tracer transport processes. Our results showed that the scale and the interaction between scale and Froude number has an effect on the hydraulics of ponds. At 1:5 scale, the increase of scale increased short-circuiting and decreased mixing. Furthermore, at 1:10 scale, the increase of scale decreased the effluent pollutant fraction. Since the Reynolds effect cannot be ignored, a ratio of Reynolds and Froude numbers was suggested to predict the effluent pollutant fraction for flows with different Reynolds numbers.

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Vidal, Jean-Philippe, Sabine Moisan, Jean-Baptiste Faure, and Denis Dartus. "Towards a reasoned 1D river model calibration." Journal of Hydroinformatics 7, no. 2 (March 1, 2005): 91–104. http://dx.doi.org/10.2166/hydro.2005.0009.

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Model calibration remains a critical step in numerical modelling. After many attempts to automate this task in water-related domains, questions about the actual need for calibrating physics-based models are still open. This paper proposes a framework for good model calibration practice for end-users of 1D hydraulic simulation codes. This framework includes a formalisation of objects used in 1D river hydraulics along with a generic conceptual description of the model calibration process. It was implemented within a knowledge-based system integrating a simulation code and expert knowledge about model calibration. A prototype calibration support system was then built up with a specific simulation code solving subcritical unsteady flow equations for fixed-bed rivers. The framework for model calibration is composed of three independent levels related, respectively, to the generic task, to the application domain and to the simulation code itself. The first two knowledge levels can thus easily be reused to build calibration support systems for other application domains, like 2D hydrodynamics or physics-based rainfall–runoff modelling.

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36

Wang, Ying, Hui Feng Zhang, Yu Shan Zhang, Ying Yao, Wei Liu, Shu Bao Gao, Rong Hua Cai, and Dan Wu. "Fluid Hydrodynamics in a Single Inlet and Multi-Inlet Hollow Fiber Module." Advanced Materials Research 217-218 (March 2011): 796–801. http://dx.doi.org/10.4028/www.scientific.net/amr.217-218.796.

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A single inlet and multi-inlet hollow fiber modules (HFMs) were designed in order to investigate the fluid hydrodynamics of the shell side. Residence time distribution (RTD) curves was measured under different packing density and inlet. Mean residence time ( ), variance( ) and the number of tanks (N) were also calculated to reflect the degree of backmixing. The experimental results indicated that the random packing of fiber caused the non-ideal flow in shell side. With the increasing of the packing density, the non-ideal flow was more serious. Contrasting to the traditional one, multi-inlet hollow fiber modules could weaken the trailing of the RTD curves and control the backmixing. With the quantity and the site of the inlets changed, non-ideal flow can be further improved. The hydraulic characterization of the shell side flow were related with not only the quantity but also the site of inlets. The results indicated that the muti-inlets design is superior to that of a single inlet.

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37

Elyaagoubi, Soukaina, Georg Umgiesser, Mehdi Maanan, Francesco Maicu, Jovita Mėžinė, Karim Hilmi, and Artūras Razinkovas-Baziukas. "Effects of Groundwater Inputs to the Hydraulic Circulation, Water Residence Time, and Salinity in a Moroccan Atlantic Lagoon." Journal of Marine Science and Engineering 10, no. 1 (January 6, 2022): 69. http://dx.doi.org/10.3390/jmse10010069.

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The finite element model SHYFEM was used to study the hydrodynamics and variability of water level, salinity, temperature, and water residence time (WRT) in the Oualidia lagoon located on the Moroccan Atlantic coast. The lagoon hosts a RAMSAR convention-protected area and also offers a set of valuable ecosystem services providing the source of income for the local population. To assess the effects of submarine groundwater discharge (SGD) inputs in the study area, four simulations were set up using different SGD inputs estimates in addition to tidal forcing, bathymetry, meteorological data including solar radiation, rain, and wind, in addition to boundary conditions in the Atlantic such as salinity, water level, and water temperature. The model was calibrated and validated using hydrodynamic measurements of previous studies in 2012 and 2013. The final results from the model are in good agreement with measured data. The simulation with SGD input ~0.05 m3 s−1 produced salinity values closest to the observed ones. Calculated spatial distribution of WRT, temperature, and salinity reduced to coordinates in two PCA axes is consistent with lagoon zones developed earlier using the benthic macroinvertebrate distribution. The calculated spatial distribution of WRT allowed us to evaluate the placement of oyster aquaculture farms and small-scale fisheries in relation to water quality issues existing in the lagoon.

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Alvarado, Andres, Esteban Sanchez, Galo Durazno, Mehul Vesvikar, and Ingmar Nopens. "CFD analysis of sludge accumulation and hydraulic performance of a waste stabilization pond." Water Science and Technology 66, no. 11 (December 1, 2012): 2370–77. http://dx.doi.org/10.2166/wst.2012.450.

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Sludge management in waste stabilization ponds (WSPs) is essential for safeguarding the system performance. Sludge accumulation patterns in WSPs are strongly influenced by the pond hydrodynamics. CFD modeling was applied to study the relation between velocity profiles and sludge deposition during 10 years of operation of the Ucubamba WSP in Cuenca (Ecuador). One tracer experiment was performed and three sludge accumulation scenarios based on bathymetric surveys were simulated. A residence time distribution (RTD) analysis illustrated the decrease of residence times due to sludge deposition. Sludge accumulation rates were calculated. The influence of flow pattern on the sludge deposition was studied, enabling better planning of future pond operation and desludging.

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39

Lu, Shibao, Wenting Cai, Wei Shao, Farhad Taghizadeh-Hesary, Muhammad Faisal, Hongbo Zhang, and Yangang Xue. "Ecological Water Requirement in Upper and Middle Reaches of the Yellow River Based on Flow Components and Hydraulic Index." International Journal of Environmental Research and Public Health 18, no. 20 (October 18, 2021): 10956. http://dx.doi.org/10.3390/ijerph182010956.

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Deterioration of the ecological environment in the upper and middle reaches of the Yellow River in China substantially impacts the growth and development of aquatic organisms in the drainage basin. This paper builds a conceptual model by applying flow components and fish ecological requirements relation with a relevant object of main fish in the upper and middle reaches of the Yellow River. The paper utilized the flow restoration method by employing the River2D model (two-dimensional model of river hydrodynamics and fish habitat), and a one-dimensional hydrodynamics HEC-RAS (hydrologic engineering center’s-river analysis system). The calculation result showed that the runoff condition required for Silurus lanzhouensis survival is that the monthly lowest flow in a year is 150 m3·s−1, and the lowest flow for suitable flow from April to October is 150 m3·s−1, and 300 m3·s−1 from November to March. The research result is closer to the actual condition and has more outstanding operability. Meanwhile, the results proposed the coupling method of ecological water requirement for the mainstream of the Yellow River. Moreover, the results portrayed the ecological flow process according to the upper envelope of minimum and maximum ecological water requirements of each fracture surface. It is regarded that the ecological flow process is deemed as the initial value of the reservoir regulation model.

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40

Meshalkin, Valery P., Nicolay A. Martsulevich, Oleg M. Flisyuk, Ilia G. Likhachev, and Antony M. Nzioka. "Hydrodynamics of Energy-Efficient Axial-Flow Cyclones for Environmentally Safe Cleaning of Gas and Dust Emissions." Energies 16, no. 2 (January 10, 2023): 816. http://dx.doi.org/10.3390/en16020816.

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We investigated the operation of an axial-flow cyclone as the most promising dust-cleaning equipment based on energy consumption. Numerical solutions were obtained for the gas-solids suspension flow equations in axial flow cyclones with different separation chambers’ geometry using FlowVision software. The chamber’s geometrical features determined the nature of the gas-solids suspension flow, directly affecting the dusty gases’ purification degree. The circulating gas flows and the turbulent “trace” after the swirl generator were found to negatively influence the cyclone efficiency and the hydraulic resistance values. A high chamber height also negatively affected the gas purification since the bulk of dust particles were removed from the gas-solids flow at the initial section. The initial section’s length coincided with the gas-solids suspension’s jet flow zone due to the flow coming off the swirl vanes’ edges. Due to turbulent mixing, the particles’ secondary entrainment and return to the gas flow began to manifest outside this zone. Based on this analysis, it is possible to develop recommendations for choosing the chamber’s geometric parameters, minimizing the influence of the indicated factors. On the basis of this research, it will be possible to ensure cyclones’ high efficiency with significantly lower hydraulic resistance when designing axial-flow cyclones relative to other types of cyclone.

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Rustum, I. M., and H. M. Soliman. "Numerical Analysis of Laminar Forced Convection in the Entrance Region of Tubes With Longitudinal Internal Fins." Journal of Heat Transfer 110, no. 2 (May 1, 1988): 310–13. http://dx.doi.org/10.1115/1.3250485.

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Steady, laminar, forced convection heat transfer in the thermal entrance region of internally finned tubes is investigated numerically for the case of fully developed hydrodynamics using the (H1) and (T) thermal boundary conditions. Results are presented for 16 geometries including the local Nusselt number and developing length corresponding to each boundary condition. These results indicate that internal finning influences the thermal development in a complicated way, which makes it inappropriate to extend the smooth tube results to internally finned tubes on a hydraulic diameter basis.

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42

Lyu, Dunyu, Chu Yu, Sha Ma, and Xiaowei Wang. "Nonlinear Seismic Response of a Hydraulic Tunnel Considering Fluid-Solid Coupling." Mathematical Problems in Engineering 2018 (November 5, 2018): 1–12. http://dx.doi.org/10.1155/2018/9608542.

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The seismic response of hydraulic tunnels is a complex nonlinear process. What makes the case even more interesting is that the large amount of water in hydraulic tunnels which is likely to induce considerable hydrodynamic pressure acted on tunnel structures during earthquakes. In this work, a full three-dimensional (3D) dynamic finite element model is adopted to conduct a comprehensive assessment of the seismic behaviors of a hydraulic tunnel system. In this analysis, the plastic-damage model is employed to reflect the nonlinear mechanical behaviors of the concrete lining, and a fluid-solid coupling method based on an explicit weighted residual approach is proposed to consider the effects of the hydrodynamic pressures on the seismic response of the hydraulic tunnel. The numerical results indicate that the hydrodynamic pressure contributes to a greater seismic response of the tunnel structure. When the hydrodynamic pressure is considered, the magnitudes of the maximum principal stresses are likely to increase by 50% and the displacement amplitudes are approximately 2 cm more than that of without hydrodynamic pressure. The hydrodynamic pressure exacerbates the damage degree of the tunnel structure, and the waist suffers the most severe damage.

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43

Meister, Michael, and Wolfgang Rauch. "Modelling aerated flows with smoothed particle hydrodynamics." Journal of Hydroinformatics 17, no. 4 (March 9, 2015): 493–504. http://dx.doi.org/10.2166/hydro.2015.132.

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Modelling aerated flows is a complex application of computational fluid dynamics (CFD) since the interfaces between air and water change rapidly. In this work, the simulation of aerated flows with the smoothed particle hydrodynamics (SPH) method is investigated with a focus towards the application in engineering practice. To prove the accuracy of the method, the processes of air entrainment and rising air bubbles are studied. Through monitoring the evolution of the bubble contours it is shown that the novel approach of adding artificial repulsion forces at the interface does not alter the dynamics but stabilizes the flow. Building on these fundamental processes we extend the discussion to practical applications with a special focus on forced aeration. Since the employment of a detailed SPH model to practical problems remains out of bounds due to the high computational demand, we propose a combined experimental and numerical study where experimental bubble characteristics are imposed on the numerical simulation. Based on the data of the conducted bubble column experiment, the computational demand is significantly decreased such that the oxygen consumption due to biokinetic processes can be modelled. The future perspective is to apply SPH to urban water systems, e.g., for simulating detailed processes in wastewater treatment and sewer hydraulics.

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Razmi, A. M., R. Bakhtyar, B. Firoozabadi, and D. A. Barry. "Experiments and numerical modeling of baffle configuration effects on the performance of sedimentation tanks." Canadian Journal of Civil Engineering 40, no. 2 (February 2013): 140–50. http://dx.doi.org/10.1139/cjce-2012-0176.

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The hydraulic efficiency of sedimentation basins is reduced by short-circuiting, circulation zones and bottom particle-laden jets. Baffles are used to improve the sediment tank performance. In this study, laboratory experiments were used to examine the hydrodynamics of several baffle configurations. An accompanying numerical analysis was performed based on the 2-D Reynolds-averaged Navier–Stokes equations along with the k-ε turbulence closure model. The numerical model was supplemented with the volume-of-fluid technique, and the advection–diffusion equation to simulate the dynamics of particle-laden flow. Model predictions compared well with the experimental data. An empirical function was constructed to indicate the location and amount of sediment collected in the tank. Hydraulic performance was determined for given baffle locations and heights. The results revealed that, for the laboratory setup, a baffle half way along its length decreases its performance, while a baffle much closer to its inlet and with height 25∼30% of water depth improves efficiency.

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Holzenthal, Elizabeth R., David F. Hill, and Meagan E. Wengrove. "Multi-Scale Influence of Flexible Submerged Aquatic Vegetation (SAV) on Estuarine Hydrodynamics." Journal of Marine Science and Engineering 10, no. 4 (April 18, 2022): 554. http://dx.doi.org/10.3390/jmse10040554.

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Bottom friction is an important process in coastal and estuarine environments because it can reduce wave heights and moderate tidal currents. When modeling large systems with spatially varying hydraulic properties, bottom friction values are commonly derived from land use classification products. However, estimation of bottom friction for vegetated areas can be more challenging due to the complicated and time-varying geometry of the roughness elements. This is particularly true of flexible, buoyant submerged aquatic vegetation (SAV) species, such as seagrasses and kelps, that deform under waves and currents. In this study we incorporate a dynamic friction model that includes the temporal variation in SAV drag forces into a depth-integrated coupled circulation-wave model. In vegetated areas, the bottom friction is continuously updated based on plant geometry, water depth, and combined wave-current velocities. Taking a multi-scale approach, we use the model to investigate the impact of SAV dynamics on both the localized and the integrated bay-wide hydrodynamics of a riverine and tidally influenced estuary. First, we investigate SAV modification of velocity fields and its implications for sediment transport and circulation pathways. Then, we show how SAV can modify tidal behavior throughout the estuary.

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Brito, Moisés, Francisco Bernardo, Maria G. Neves, Diogo R. C. B. Neves, Alejandro J. C. Crespo, and José M. Domínguez. "Numerical Model of Constrained Wave Energy Hyperbaric Converter under Full-Scale Sea Wave Conditions." Journal of Marine Science and Engineering 10, no. 10 (October 14, 2022): 1489. http://dx.doi.org/10.3390/jmse10101489.

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A 2D numerical investigation of the power absorption of a constrained wave energy hyperbaric converter (WEHC) under full-scale sea wave conditions is presented. A fully non-linear numerical model DualSPHysics, based on the coupling of a smoothed particle hydrodynamics (SPH) fluid solver with a multibody dynamics solver, is used to model the interaction between wave and WEHC sub-systems. The numerical model was first validated against experimental data for a similar device, with a good accordance between PTO position and velocity. The model is then employed to study the hydrodynamics of a constrained WEHC considering several sea states, different hydraulic power take-off (PTO) damping and breakwater geometries. It is observed that the capture width ratio (CWR) is particularly sensitive to variations in the PTO damping, although the CWR absolute maximum is less sensitive considering mild variations applied to the PTO damping. Both wave height and wave period have an important effect on the CWR. The breakwater geometry is also essential for the performance of the WEHC, with a decrease in maximum CWR of about 15% for porous breakwater. These results are necessary to understand the full-scale behaviour of WEHC.

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47

Lai, Wenbin, Detang Li, and Yonghe Xie. "Simulation and Experimental Study of Hydraulic Cylinder in Oscillating Float-Type Wave Energy Converter." Polish Maritime Research 27, no. 2 (June 1, 2020): 30–38. http://dx.doi.org/10.2478/pomr-2020-0024.

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AbstractHydraulic cylinders play a vital role in the energy output (PTO) system of an oscillating float-type wave energy converter, whose function is to convert the mechanical energy captured by the float from the waves into hydraulic energy. The performance of the hydraulic cylinder determines the conversion efficiency of mechanical energy to hydraulic energy in the system; therefore, it is necessary to study the working mechanism of the hydraulic cylinder. This paper takes a self-developed oscillating float-type wave energy converter as the research object, and studies the working mechanism of its hydraulic cylinder, and uses the linear analysis method to derive the critical self-excited vibration curve of the hydraulic cylinder. In addition, the effects of the external load, hydraulic cylinder load mass, stroke length, spring stiffness and piston area on the performance of the hydraulic cylinder were studied by AMESim simulation software. According to the simulation results, a physical model of the hydraulic cylinder is established. Finally, the physical model is tested in a hydrodynamic pool. The test results show that the hydraulic cylinder can stably and efficiently convert mechanical energy into hydraulic energy even under small waves, thus verifying the rationality of the hydraulic cylinder design.

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Elsheikh, Nuri, Amir H. Azimi, Ioan Nistor, and Abdolmajid Mohammadian. "Tsunami-Induced Bores Propagating over a Canal, Part II: Numerical Experiments Using the Standard k-ε Turbulence Model." Fluids 7, no. 7 (June 22, 2022): 214. http://dx.doi.org/10.3390/fluids7070214.

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This companion paper presents the results of a series of numerical experiments examining the effects of a mitigation canal on the hydrodynamics of a tsunami-like turbulent bore proceeding over a horizontal bed. The hydraulic bores were generated by a dam-break setup which employed impoundment depths of do = 0.20 m, 0.30 m, and 0.40 m. The bore propagated downstream of the impoundments in the flume and interacted with a canal with varying geometry located downstream. The bore then left the flume through a drain located further downstream of the canal. In this study, the effect of the canal depth on the specific momentum and specific energy of hydraulic bores passing over a rectangular canal is numerically studied. The canal width was kept constant, at w = 0.6 m, while the canal depths were varied as follows: d = 0.05 m, 0.10 m, and 0.15 m. The time history of mean flow energy during the bore’s passing over the mitigation canal indicates that the jet stream of the maximum mean flow energy is controlled by the canal depth. The time required to dissipate the jet stream of the maximum vorticity, the turbulent kinetic energy, and the energy dissipation rate all increased as the canal depth decreased. The effect of canal orientation on the bore hydrodynamics was also numerically investigated, and it was found that the impulsive momentum and specific energy reached the highest values for canal orientations of 45 and 60 degrees. For the same canal depth, the highest peak specific momentum occurred with the highest degree of canal orientation (θ = 60°).

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Demeke, Getnet Kebede, Dereje Hailu Asfaw, and Yilma Seleshi Shiferaw. "3D Hydrodynamic Modelling Enhances the Design of Tendaho Dam Spillway, Ethiopia." Water 11, no. 1 (January 4, 2019): 82. http://dx.doi.org/10.3390/w11010082.

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Hydraulic structures are often complex and in many cases their designs require attention so that the flow behavior around hydraulic structures and their influence on the environment can be predicted accurately. Currently, more efficient computational fluid dynamics (CFD) codes can solve the Navier–Stokes equations in three-dimensions and free surface computation in a significantly improved manner. CFD has evolved into a powerful tool in simulating fluid flows. In addition, CFD with its advantages of lower cost and greater flexibility can reasonably predict the mean characteristics of flows such as velocity distributions, pressure distributions, and water surface profiles of complex problems in hydraulic engineering. In Ethiopia, Tendaho Dam Spillway was constructed recently, and one flood passed over the spillway. Although the flood was below the designed capacity, there was an overflow due to superelevation at the bend. Therefore, design of complex hydraulic structures using the state-of- art of 3D hydrodynamic modelling enhances the safety of the structures. 3D hydrodynamic modelling was used to verify the safety of the spillway using designed data and the result showed that the constructed hydraulic section is not safe unless it is modified.

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SHLYAPKIN, Alexey S., and Alexey V. TATOSOV. "NUMERICAL AND PROGRAM IMPLEMENTATION OF A ONE-DIMENSIONAL MATHEMATICAL MODEL OF HYDRAULIC FRACTURING." Tyumen State University Herald. Physical and Mathematical Modeling. Oil, Gas, Energy 7, no. 1 (2021): 126–45. http://dx.doi.org/10.21684/2411-7978-2021-7-1-126-145.

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Abstract:

At present, an active policy of import substitution is being pursued, dictated by the imposed international sanctions, which creates a need for finding optimal engineering solutions, in particular, in the field of creating Russian software. In the study and design of hydraulic fracturing, they often rely on the results of modeling in specialized simulators. The appearance of the Russian products on the software market, surely, sets the correct vector of development; however, some aspects are not implemented in the existing mathematical models. The authors of this article present a model that allows considering in detail the process of movement of proppant particles in a hydraulic fracture. The chosen direction is important from the point of view of calculating the fracture cavity and refining its productivity, since the behavior of the particles has a significant effect on both the growth potential of the crack and its shape. The research methodology includes a theoretical justification of the mathematical model presented by the authors in their previous works; a description of the basic principles of selecting and constructing a numerical calculation scheme and creating a software package. The main methods of research are the methods of mathematical modeling, formed from practical problems on the estimation of geometric parameters of the crack, including the areas of continuum mechanics and fracture of solids, underground hydrodynamics. The proposed and implemented numerically mathematical model forms the basis of the authors’ software package, which allows solving the main design problems when performing hydraulic fracturing operations.

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Journal articles on the topic 'Hydrodynamics and hydraulic engineering'

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