CFD Simulation of Ground Vortex Intake Test Case using ANSYS FLUENT

Computational fluid dynamics (CFD) simulation results are presented for the canonical test case of flow over a backward facing step (BFS). The BFS case exhibits complex physics including turbulent separation, reattachment, and boundary layer restart. Results are obtained using two different turbulence models as representative examples of two classes of modeling: Reynolds-averaged Navier-Stokes (RANS) and hybrid RANS-LES (large-eddy simulation). The specific models used are k-ω SST and dynamic hybrid RANS-LES (DHRL). The objective of the study is to compare the performance of both turbulence models as implemented in three different flow solvers (Flow Psi, Loci-CHEM, and Ansys FLUENT) and using three different methods for numerical discretization of the convective terms in the governing equations. Results are compared to experimental data for validation purposes. Results show that both k-ω SST and DHRL models are capable of reproducing the mean flow physics with reasonable accuracy. The differences due to solver algorithm and convective discretization scheme are apparent for both models, but the DHRL model shows more sensitivity, as expected. Overall the results highlight the importance of considering all integrated aspects of a turbulent CFD simulation to ensure that an optimum combination of model and numerical method are employed.

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The study of the numerical diffusion in computational calculation

MATEC Web of Conferences ◽

10.1051/matecconf/202031000039 ◽

2020 ◽

Vol 310 ◽

pp. 00039

Author(s):

Kamila Kotrasova ◽

Vladimira Michalcova

Keyword(s):

Heat Transfer ◽

Differential Equation ◽

Numerical Simulation ◽

Continuity Equation ◽

Cfd Simulation ◽

Flow Process ◽

Ansys Fluent ◽

Numerical Diffusion ◽

Mesh Density ◽

Computational Calculation

The numerical simulation of flow process and heat transfer phenomena demands the solution of continuous differential equation and energy-conservation equations coupled with the continuity equation. The choosing of computation parameters in numerical simulation of computation domain have influence on accuracy of obtained results. The choose parameters, as mesh density, mesh type and computation procedures, for the numerical diffusion of computation domain were analysed and compared. The CFD simulation in ANSYS – Fluent was used for numerical simulation of 3D stational temperature flow of the computation domain.

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Geometric Modeling of a Propeller Turbine Runner Using ANSYS BladeGen, Meshing Using ANSYS TurboGrid and Fluid Dynamic Simulation Using ANSYS Fluent

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.842.164 ◽

2016 ◽

Vol 842 ◽

pp. 164-177 ◽

Cited By ~ 2

Author(s):

Indra Djodikusumo ◽

I. Nengah Diasta ◽

Iwan Sanjaya Awaluddin

Keyword(s):

Geometric Modeling ◽

Cfd Simulation ◽

Fluid Dynamic ◽

Thickness Distribution ◽

Ansys Fluent ◽

Implementation Phase ◽

Runner Blade ◽

Modeling Process ◽

Turbine Runner ◽

Preparation Phase

This paper aims to demonstrate how to model, mesh and simulate a hydraulic propeller turbine runner based on the geometrical specification of the runner blade. Modeling process is divided into preparation and implementation phase. Preparation phase illustrates how to develop stream surfaces and passages, how to create and transform meanline and how to create an rtzt file. The profile in rtzt file has a certain fix thickness which has to be altered later. Implementation phase describes operations necessary in creating a propeller runner model in ANSYS BladeGen which consist of importing rtzt file, modifying the trailing edge properties and altering profile thickness distribution to that of 4 digits NACA airfoil standard. Grid is generated in ANSYS TurboGrid utilizing ATM Optimized topology. CFD simulation is done using the ANSYS Fluent with pressure inlet and pressure outlet boundary conditions and k-ε turbulence model. Hydraulic efficiency of the runner is calculated utilizing Turbo Topology module in ANSYS Fluent. The authors will share the advantages that may be obtained by using ANSYS BladeGen compared with the use of general CAD Systems.

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Calculated research of aeroelastic stability of a bridge over the river Ob in Salekhard at the stage of assembling and operation

Russian journal of transport engineering ◽

10.15862/13sats319 ◽

2019 ◽

Vol 6 (3) ◽

Author(s):

Anastasiya Shustikova ◽

Andrei Kozichev ◽

Sergei Paryshev ◽

Konstantin Strelkov

Keyword(s):

Cfd Simulation ◽

Load Capacity ◽

Air Flow ◽

Lift Coefficient ◽

High Strength ◽

Railway Bridge ◽

Aeroelastic Stability ◽

Ansys Fluent ◽

Long Span ◽

Long Span Bridge

Recently, long span bridge construction has been demanded for development of the regions of the Russian Federation. In terms of economy, it’s useful to build a combined road-railway bridge. Such bridges, generally, constitute a metal cross-cutting girder with carriageways on lower, upper or both zones of the girder. The major advantages of combined bridges are high strength and load capacity, plus cross-cutting to wind load. Focus of this research is a combined road-railway bridge over the Ob river at the stage of assembling and operation. The purpose of the study was to determine the limits of aeroelastic stability of combined road-railway bridge at the stage of assembling and operation using numerical simulation. To better understand the bridges behaviour in air flow, flow around a section model has been researched with CFD simulation in the ANSYS FLUENT. Then based on the given results of the calculations the dependence of the bridge vibrations on wind speed within a specified range is obtained, and also values of drag coefficient Сх, lift coefficient Су and torque coefficient Мz are received. These studies were carried out in the range of angles of attack α = ±3°. The possibility of divergence and galloping was also estimated. The results of the study made it possible to estimate the influence of air flow on combined bridge cross-cutting girder. Overall, the conducted research seems promising for further investigation and development in the field of bridge aeroelasticity.

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EFFECT OF GALLERIES ON THE WIND FLOW STRUCTURE AND POLLUTANT TRANSPORT WITHIN STREET CANYONS WITH OR WITHOUT FACADE ROUGHNESS ELEMENTS (BALCONIES)

International Journal of Engineering Technologies and Management Research ◽

10.29121/ijetmr.v7.i12.2020.835 ◽

2020 ◽

Vol 7 (12) ◽

pp. 45-59

Author(s):

V. A. Karkoulias ◽

P. E. Marazioti ◽

D. P. Georgiou ◽

E. A. Maraziotis

Keyword(s):

Flow Field ◽

Concentration Distribution ◽

Cfd Simulation ◽

Field Structure ◽

Flow Structures ◽

Street Canyons ◽

Ansys Fluent ◽

Roughness Elements ◽

Computational Fluid Dynamics Cfd ◽

The Vertical Distribution

This paper investigates how the structure of the flow field and the vertical distribution of the pollutant concentration near the wall facades of street canyons are affected by the presence of some elements such as street level galleries. Numerical results are presented for various gallery geometries in combination with facade roughness elements (balconies) for a canyon of an aspect ratio equal to h/w=2.33. The results were obtained by a Computational Fluid Dynamics (CFD) simulation employing the ANSYS-FLUENT suite that incorporated the k-e turbulent (RNG) model. The simulation generated several flow structures inside the canyon (mainly vortices), whose characteristic properties (e.g. number, strength and size) are discussed in terms of the effect of the galleries on the flow field structure and the roughness generated by the building façade balconies. The results indicate a significant influence on both the flow field structure and the mass concentration distribution of the polluting particles.

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CFD investigation on the performance analysis of Tesla turbine

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/850/1/012026 ◽

2021 ◽

Vol 850 (1) ◽

pp. 012026

Author(s):

J Kevin Joseph ◽

R Jeyanthinathan ◽

R Harish

Keyword(s):

Power Output ◽

Cfd Simulation ◽

Simulation Software ◽

Working Fluid ◽

Maintenance Cost ◽

Ansys Fluent ◽

Rotating Speed ◽

Velocity Magnitude ◽

Turbine Disc ◽

Improved Performance

Abstract A Tesla turbine is a bladeless turbine in which fluid flows in the direction of the centripetal path. It uses fluid properties such as Boundary layer & adhesion of fluid on a series of discs keyed to a shaft. The initial cost and maintenance cost of the Tesla turbine is very low. Our project’s main motive is to improve the performance of a Tesla turbine by changing various parameters such as disc diameter and disc rotating speed through the CFD simulation software using water as a working fluid. The CAD model is designed using Ansys design modeler, meshing is performed using Ansys meshing and post processing is carried out in Ansys fluent. The numerical simulations were carried out using Ansys Fluent which is based on the finite volume method and the changes that occurred in the pressure and velocities are investigated. The parametric study is performed by varying the turbine disc speed. By performing CFD simulations, total pressure contour and velocity magnitude contours are plotted and it is found that pressure and velocity are maximum when the clearance between disc and turbine casing is lesser and at higher turbine disc speeds. The power output of the Tesla turbine is also plotted for various rpm where higher rpm gives maximum power output. The results from the present study would be useful in designing an efficient Tesla turbine with improved performance.

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Computer Analysis of S822 Aerofoil Section for Blades of Small Wind Turbines at Low Wind Speed

Journal of Solar Energy Engineering ◽

10.1115/1.4037484 ◽

2017 ◽

Vol 139 (5) ◽

Cited By ~ 3

Author(s):

Prachi R. Prabhukhot ◽

Aditya R. Prabhukhot

Keyword(s):

Wind Speed ◽

Wind Turbine ◽

Cfd Simulation ◽

Maximum Velocity ◽

Small Scale ◽

Blade Profile ◽

Ansys Fluent ◽

Low Wind Speed ◽

Upward Direction ◽

Computational Fluid Dynamics Cfd

The power generated in wind turbine depends on wind speed and parameters of blade geometry like aerofoil shape, blade radius, chord length, pitch angle, solidity, etc. Aerofoil selection is the crucial factor in establishing the efficient wind turbine. More than one aerofoil in a blade can increase the efficiency further. Previous studies of different aerofoils have shown that efficiency of small scale wind turbine increases when NREL S822 aerofoil is used for wind speed on and above 10 m/s. This paper introduces a study on effect of low wind speed (V = 5 m/s) on performance of blade profile. Aerofoils NREL S822/S823 are used for microwind turbine with S823 near root and S822 near tip. Blade of 3 m radius with spherical tubercles over entire span is analyzed considering 5 deg angle of attack. The computational fluid dynamics (CFD) simulation was carried out using ANSYS fluent to study the behavior of blade profile at various contours. The study shows that blade experiences maximum turbulence and minimum pressure near trailing edge of the tip of blade. The region also experiences maximum velocity of the flow. These factors result in pushing the aerofoil in upward direction for starting the wind turbine to rotate at the speed as low as 5 m/s.

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An Investigation of Methane Combustion in a Rectangular Shaped Meso Chamber

Volume 8A: Heat Transfer and Thermal Engineering ◽

10.1115/imece2014-39810 ◽

2014 ◽

Author(s):

Mahbub Ahmed ◽

Cheng Zhang ◽

Scott McKay ◽

Vivek Shirsat ◽

Jobaidur Khan

Keyword(s):

Cfd Simulation ◽

Methane Combustion ◽

Ansys Fluent ◽

Flamelet Model ◽

Power Generators ◽

Rich Condition ◽

Higher Power ◽

Fluent Software ◽

Finite Volume Approach ◽

Power Densities

Hydrocarbon-based miniature power generators are promising any many application since hydrocarbon based fuels have higher power densities compared to conventional lithium batteries. A 40mm long meso-combustor of two different configurations, two-inlet and three-inlet, were used to investigate the combustion of methane in the meso-chamber. A non-premixed combustion of methane and oxygen was simulated numerically using a steady laminar flamelet model. The mesh generation and the CFD simulation were performed using ANSYS FLUENT software. A a finite volume approach was used for the simulation. The fuel-oxidizer mixing, thermal behavior and fuel burning efficiency were studied. An adequate mixing that supports the combustion was observed in certain locations. The exhaust gas was analyzed experimentally. The temperature distributions were also observed to predict the flame locations. According to the numerical analysis it was apparent that the flame would be anchored in the well mixed regions of the chamber the flames were found to be attached in two distinct locations. One in the upstream zone and the other one in the downstream zone. Another important finding was that the fuel lean condition produced higher efficiency than the fuel rich condition.

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Thermal Diffusion Performance of a Diffuser by various Guide Vanes configurations

MATEC Web of Conferences ◽

10.1051/matecconf/201822503018 ◽

2018 ◽

Vol 225 ◽

pp. 03018

Author(s):

Aja O. Chikere ◽

Hussain H. Al-Kayiem ◽

Zainal Ambri A. Karim

Keyword(s):

Gas Flow ◽

Cfd Simulation ◽

Bench Mark ◽

Ansys Fluent ◽

Guide Vanes ◽

Pressure Losses ◽

Fluent Software ◽

Thermal Diffuser ◽

Crosssectional Area ◽

Large Diffusion

The use of vane-less diffuser with large diffusion angle has shown a setback in the diffusion process of high temperature working fluids. The hot gas flow was characterized as a jet-like flow. This paper presents problem, encountered practically, using a vane-less diffuser with large diffusion angle and how the problem is solved by CFD simulation. The investigated thermal diffuser has a length of 0.3 m, an inlet to outlet crosssectional area ratio of 1:25 and diffusion angle of 115.44o. To resolve the jet-like flow problem and poor distribution of the flow temperature at the diffuser outlet, the study suggested the use of guide-vanes into the diffuser. The study employed CFD simulation by ANSYS-FLUENT software to analyze the flow and thermal process in the diffuser. Three different shapes of guide vanes; block-shaped, oval-shaped and airfoil-shaped were considered in this study and at different vanes diffusion angles, as well as vane-less case, which was adopted as the bench mark case. The simulation results of the velocity, temperature and pressure at the diffuser outlet were compared for all cases. It was found that the guide vanes with symmetrical airfoil profile provided the best performance with most uniform distribution at the outlet of the diffuser. Also, the airfoil-shaped guide vanes resulted in lower pressure losses compared to the block-shaped and oval-shaped guide vanes. According to the analysis results, the diffuser was redesigned to improve the diffusion and temperature distribution across the diffuser outlet.

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