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CFD analysis of performance improvement of the Savonius water turbine by using an impinging jet duct design

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Chinese Journal of Chemical Engineering 2019年第4期27卷 794-801页

作者： Narendra Thakur Agnimitra Biswas Yogesh Kumar Mithinga Basumatary Mechanical Engg.Deptt. NIT Silchar

The majority of research on water turbines focuses on design improvement of large-scale hydrokinetic turbines for power generation, which may have delayed the utilization of kinetic energy contained in rivers and canals. The aim of this paper is to improve the efficiency of a two bladed Savonius type cross-flow hydrokinetic turbine, which can be used as an energy converter to harness free-stream kinetic energy of water. An impinging jet duct design is presented for improving performance of the Savonius turbine in wind application as seen from literature. The performance of the modified turbine is evaluated using CFD software Fluent, and is compared with that of a simple two bladed Savonius water turbine and some of the prominent literature designs of the Savonius turbine. It is shown that the present design exhibits improved performance compared to the selected designs of the Savonius *** an insight of the improved performance of the modified turbine is also obtained from flow physics study.

关键词： Savonius water turbine CFD impinging jet duct design Power coefficient Water power Flow physics

Application of a k-ε Model to Heat Transfer in impinging Flows

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Journal of Thermal Science 2004年第1期13卷 62-66页

作者： Bart Merci Chris De Langhe Koen Lodefier Erik Dick Ghent University Dept.of FlowHeat and Combustion MechanicsSint-Pietersnieuwstraat 41B-9000 GentBelgiumGhent UniversityDept.of FlowHeat and Combustion MechanicsSint-Pietersnieuwstraat 41B-9000 GentBelgiumGhent UniversityDept.of FlowHeat and Combustion MechanicsSint-Pietersnieuwstraat 41B-9000 GentBelgiumGhent UniversityDept.of FlowHeat and Combustion MechanicsSint-Pietersnieuwstraat 41B-9000 GentBelgium

Local heat transfer is predicted in turbulent axisymmetric jets, impinging onto a flat plate. A non-linear k-e model is used, in which both the constitutive law for the turbulent stresses and the transport equation for the turbulent dissipation rate e have an important contribution in the improved heat transfer predictions. The shape of the Nusselt number profiles, expressing dimensionless heat transfer, as well as the stagnation point value, are well predicted for different distances between the nozzle exit and the plate. Accurate flow field predictions are the basis for good heat transfer predictions. For a fixed Reynolds number, the influence of the nozzle-plate distance is well captured. For a fixed distance, the influence of the Reynolds number is correctly reproduced. Comparisons are made to a low-Reynolds standard k-e model and the v2-f model. A thorough discussion is found in [4]. Only a summary of those results is discussed here, while some new results are also presented.

关键词： local heat transfer impinging jets non-linear k-ε model.

Experimental investigation of submerged impinging jets in a plunge pool downstream of large dams

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Science China(Technological Sciences) 1998年第4期41卷 357-365页

作者：刘沛清高季章李永梅 China Institute of Water Conservancy and Hydroelectric Power Research Beijing China

Submerged impinging jets in a plunge pool downstream of large dams are experimentally investigated in details. By use of the hot\|film anemometer, the velocity field in the plunge pool produced by middle orifices of 1∶400 scale Xiluodu spillway model is measured. The diffusive characteristics and energy dissipation mechanism of the submerged impinging jet in the plunge pool are analyzed.

关键词： impinging jet plunge pool energy dissipation.

An Exact Solution for Heat Transfer of a Jet Co-Axially impinging on a Rotating Disk and Its Comparisons with Stagnation Point Experiments

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Journal of Thermal Science 2002年第1期11卷 53-59页

作者： I.V. Shevchuk (Institute of Engineering Thermophysics, Ukrainian National Academy of Sciences, 2a, Zhelyabov St., Kiev, 03057, Ukraine. E-mail: ivshevch@i.com.ua) Institute of Engineering Thermophysics Ukrainian National Academy of Sciences Ukraine

An exact solution of laminar heat transfer problem for a uniform flow perpendicular to a rotating disk was obtained. Radial velocity at the outer edge of the boundary layer increases linearly in the radial direction, while the temperature difference between the disk and outer flow follows a power law. The problem is solved using self-similar velocity and temperature profiles. Nusselt numbers were computed for the Prandtl numbers Pr=1 and 0.71 at different values of parameters affecting flow and heat transfer. Special flow regime was identified where rotating disk heat transfer is determined only by peculiarities of the impinging flow. Results of predictions agree well with known experiments in the vicinity of the stagnation point.

关键词： impinging jet rotating disk Nusselt number laminar flow heat transfer boundary layer exact solution

Effect of impinging angle and rotating speed on erosion behavior of aluminum

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Transactions of Nonferrous Metals Society of China 2011年第1期21卷 32-38页

作者： A.K.JHA R.BATHAM M.AHMED A.K.MAJUM DER O.P.MODI S.CHATURVEDI A.K.GUPTA Advanced Materials and Processes Res earch Institute

Commercial aluminum（grade 1900） in rotary motion was exposed to slurry of sand in *** were mounted at various angles and rotated at different *** rate was calculated using mass loss *** results show that wear rates increase with increasing impingement angle up to 90°.Contrary to the conventional understanding of maximum loss of ductile material at about 45° impingement angle,maximum wear rate was observed in case of the aluminum sample fixed at 90°.However,increasing rotation speed of the samples results in exponential increase in wear *** findings are substantiated with the metallographic study of worn surface.

关键词： aluminum slurry erosion impinging wear

Forced Electrocodeposition of Silica Particles into Nickel Matrix by Horizontal impinging Jet Cell

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Journal of Materials Science and Chemical Engineering 2017年第2期5卷 51-63页

作者： Désiré M. K. Abro Pierre Jean Marie Richard Dable Véronique Amstutz Edith Kouassi Kwa-Koffi Hubert Girault Faculté des Sciences des Structures de la Matiè re et de Technologie Universit&eacute Fé lix HOUPHOUET-BOIGNY Abidjan C&ocirc te d'Ivoire Dé partement de Gé nie Mé canique et Energé tique Institut National Polytechnique F&eacute lix HOUPHOUET-BOIGNY Yamoussoukro C&ocirc te d'ivoire Institut des sciences et ingé nierie chimiques Ecole Polytechnique F&eacute dé rale de Lausanne Sion Suisse

The improvement of silica particle codeposition into a nickel electrodeposited composite coating (ECC) by a double face horizontal impinging jet cell (IJC) has been studied. The microstructure of coatings was examined by means of scanning electron microscopy performed in backscattered electron mode. The embedded particles distribution was shown to be the densest and the most uniform in laminar low flow mode and when the nozzle is at a distance of 5 mm close from the cathode. Excrescences observed on the composite surface are due to the wave-like flow of the jet on the cathode surface. The silica content of the nickel composite coatings was assessed by energy dispersive X-ray spectroscopy. The amount of particles embedded in the coating decreases with an increasing Reynolds number and as the nozzle-to-sample distance d becomes larger. A maximum rate of 4.43 wt% of silica has been successfully loaded at a distance d equal to 5 mm in the Ni-SiO2 composite coating.

关键词： Electrocodeposition Nickel-Silica Composite Coatings impinging Jet Cell Hydrodynamics

Experimental Study of Two impinging Jets Aligned With a Crossflow

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Journal of Modern Physics 2014年第16期5卷 1779-1788页

作者： Jorge M. M. Barata Fernando M. S. P. Neves Diana F. C. Vieira André R. R. Silva Universidade Beira Interior Covilha Portugal

Laser Doppler measurements provide information on the flowfield created by twin impinging jets aligned with a low velocity crossflow. The experiments were carried out for a Reynolds number based on the jet exit conditions of Rej = 4.3 × 104, an impingement height of 20.1 jet diameters and for a velocity ratio between the jet exit and the crossflow VR = Vj/Uo of 22.5, and an inter-jet spacing of S = 6D. The results show a large penetration of the first (upstream) jet that is deflected by the crossflow and impinges on the ground, giving rise to a ground vortex due to the collision of the radial wall and the crossflow that wraps around the impinging point like a scarf. The second jet (located downstream) is not so affected by the crossflow in terms of deflection, but due to the downstream wall jet that flows radially from the impinging point of the first jet it does not reach the ground. The results indicate a new flow pattern not yet reported so far, that is most relevant for a VSTOL aircraft operating in ground vicinity with front wind or small forward movement may result in enhanced under pressures in the aft part of the aircraft causing a suction down force and a change of the pitching moment towards the ground.

关键词： impinging Jets Crossflow

Nitrogen Dilution and Extinction Effects for Methane impinging Diffusion Flame

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Nitrogen Dilution and Extinction Effects for Methane Impingi...

Numerical Analysis of the Flow Field of an Inclined Turbulent impinging Jet

2012 2nd Internationnall Conference on Mechanical, Industrial, and Manufacturing Engineering

作者： Nadjib Ghiti Abed Alhalim Bentebbiche Ramzi Boulkroune Laboratoire de Mecanique Avancee—LMA URASM-CSC/ANNABA Unite de recherche Appliquee en Siderurgie Metallurgie Centre National de Recherche Scientifique et Technique en Soudage et Controle

In this study we focus an experimental investigation on the effect of the dilution rate on the extinction of a methane diffusion impinging *** infrared thermography camera to show the flame flow structure and to analysis the flow wall interacting behavior,with the variation of the nitrogen added rate to the methane jet flame by 0.2N,0.4N,0.6N,*** temperature fluctuation was shown a turbulent behavior of the flame and the extinction is more dependent on the flame approaching to the impinging wall and with the increase of the dilution rate,more dilution that is short time to extinction limit.

关键词： turbulence dilution diffusion flame impinging methane

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海外英语 2013年第17期 293-296页

作者：魏宏静贵州省铜仁职业技术学院

A three-dimensional numerical study has been applied to examine the effects of impinging angle of incline impinging jet on heat transfer and flow field characteristic. Other parameters such as nozzle to plate distance and jet velocity and temperature are also examined to investigate their influences on jet flow. The impinging angle in range of 900-650, the nozzle exit-to-plate spacing(H/D) in range of 2 to 10, the Reynolds number in range of 1.27x102to 1.27x104and the jet temperature in range of323K to 773K have been considered in this project.

关键词： impinging Jet Turbulence Heat transfer