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Comparison of Turbulence Models in the Simulation of Fluid Flow in Corrugated Channel Aimen Tanougast1,a*, Krisztián Hriczó1,b 1Institute of Mathematics, Faculty of Mechanical Engineering and Informatics, University of Miskolc, Miskolc-Egyetemvaros, Miskolc, H--3515, Hungary atanougast.aimen@uni-miskolc.hu, bkrisztian.hriczo@uni-miskolc.hu Keywords: Turbulence, corrugated channel, vortex generators, k-ε, k-ω, Reynolds Stress Model (RSM), CFD.
Vortex generators are known to enhance heat transfer by promoting flow separation and modifying the flow direction, making their effect critical in such simulations.
Turbulence models provide the necessary approximations for Reynold’s stress, enabling the accurate simulation of turbulent flows [1].
· Two-dimensional simulation (∂∂x3=0 and u3=0)
CFD Letters, 11(10), 69-80

This paper summarizes the two methods which are experimental research and numerical simulation to thermal environment of the tunnel.
In addition, the solving accuracy of numerical simulation is closely related to the operator, so it has great subjectivity.
The three-dimensional model established on the CFD software is shown in Figure 1.The whole computational domain is 15*500*20m which consist of soil horizon and concrete layer.
Through CFD software, the radial temperature distribution of surrounding rock and the axial temperature distribution of air at winter and summer conditions are obtained.
Research on Simulation and Evaluation System of Energy Conservation for Tunnel Ventilation System[J].

Currently, the way to know the wind load both home and abroad includes field measurement, wind tunnel test simulation and computer analogue simulation.
Based on the existing research findings and by taking assembled steel truss bridge as the research object, the method of computational fluid dynamics (CFD) is used to make numerical simulation for the stochastic wind field.
Governing equation and numerical method Computational Fluid Dynamics (CFD) is the analysis made to the system of physical phenomenon including fluid flow and heat conduction by means of computer numerical calculation and image display.
Based on correlation theory and method of CFD, the workflow of the numerical simulation of the stochastic wind field of assembled steel truss bridge is shown in chart 1.
Analysis of Computational Fluid Dynamics- Calculation Principle and Application of CFD Software [M].

Y-shaped tee is modeled by three-dimensional graphics software and its flow field is analyzed and numerical simulated by CFD software.
Simulation results are consistent to the practice, which provides important theoretical basis for improving and optimization of Y-shaped tee.
By the using of CFD software, the geometric model of Y-shaped tee is meshed.
With the case studied in this essay, it is thus clear that the method of simulation analyzing of fluid-structure coupling for Y-shaped tee is feasible by using CFD software.
It can be popularized in the other flow field simulation analysis.

Table 1 shows the main parameters of CFD simulation test including the physical properties of crude oil.
The simulation test operated until reaching the steady state condition.
The results from developed CFD simulation program were already validated with the commercial program ANSYS FLUENT [9].
The parameters for CFD simulation test.
The simulation results showed that those all 8 profiles had quite similar patterns.

In this paper, a novel dynamic de-oiling oil-water separator was proposed, and through Computational Fluid Dynamics (CFD) simulation, the effects of the pressure drop ratio on the separation efficiency and the split ratio were analyzed.
Numerical Simulations Fig. 1 Simplified model for simulation Table 1 Main dimensions of the simulation model DI(mm) Di/DI Do/DI Du/DI L1/DI L2/DI L3/DI L4/DI α() 70 3/7 3/15 3/7 53/7 25/7 10/7 1/7 10 Fig. 2 Meshes of the simulation model Determination of Boundary and Operation Conditions.
The simplified simulation model is shown in Fig. 1.
The final meshing for the simulation is shown in Fig. 2.
Though the numerical simulation works, the following results could be obtained.

Wind Speed/(m/s-1) Human Senses V＜5 Cozy 5＜V＜10 Uncomfortable,action affected 10＜V＜15 Quite uncomfortable,action to be seriously affected 15＜V＜20 Insupportableness V＞20 Dangerous The Meteorological Data and CFD Computational Fluid Dynamics Analysis The Meteorological Data.
The Analysis of CFD Computational Fluid Dynamics.
Numeral simulation of fluid flow is that solving fluid dynamics equations discretly,which are obeyed by air flow,and display the result visually with computer graphics techniques.The numerical simulation technique is called computational fluid dynamics（CFD：Computational Fluid Dynamics）technique.
Since 1974, people have carried out the CFD technology application into the simulation and research work of building environment.With the development of computer technology,CFD with its low pay,convenience is applied widely.
References [1] R.Yoshie,A.Mochida:Journal of Wind Engineering and Industrial Aerodynamics,Vol.95(2007), p.1551 [2] Yoshihide Tominaga:Journal of Wind Engineering and Industrial Aerodynamics,Vol.96(2008), p.1749 [3] Li Baofeng, Architectural Design Ecological Strategy, Beijing: Tsinghua University, 2004:31,in Chinese [4] Lee Kun, Yu Zhuang, Wuhan Regional Wind Environment Influence in the Simulation Analysis of the Temperature, Beijing: resources science, 2006, 28 ( 6) :51-59,in Chinese [5] C.W.Tsang,K.C.S.Kwok,P.A.Hitchcock:Bilding and Environment,Vol.49(2012),p.167 [6] Yoshie,R,“CFD analysis of flow field around a high-rise building”,in Summaries of Technical Papers of Annual Meeting,Environ,Engg, II, AIJ,(1999),in Japanese [7] Kataoka,H,“Large Eddy Simulation of building”,in Summaries of Technical Papers of Annual Meeting,Environ,Engg,II,AIJ,(2003),in Japanese [8] Information on http://www.abbs.com.cn/

Spalart-Allmaras one-equation turbulent model was used for simulations.
It is clear to see that the lift coefficient of the present CFD results are in fair agreement with the experimental data.
(a) CL～α (b) CD～α Fig. 6 M=1.89，comparison between the experimental data and CFD results M=1.5 results.
High-pressure shock tunnel experiment and CFD calculations on spike-tipped blunt bodies, AIAA-2002-2918
Numerical Simulation of Self-Sustained Oscillations Over Spiked Blunt-Bodies.

The lattice Boltzmann method (LBM) is relatively novel and contrasts with the usual well-known methods to physical modeling in the domain of computational fluid dynamics (CFD).
Indeed two different matters with special ingredients and ideas are handled when the LBM is considered to physical modeling in the CFD domain instead of the usual numerical methods.
Dimensionless parameters used in the simulation and their characteristic values, calculated for SiGe solution, are predicted from [47].
The present LBE-based model is found numerically more efficient than usual CFD methods under particular situations.
[27] Swift, M.R.; Orlandi, E.; Osborn, W.R.; Yeomans, J.M. (1996): Lattice Boltzmann simulations of liquid–gas and binary fluid systems.

Simulations consider two types; i.e.
The pressure loss ‘cold’ test simulations consider ambient inlet air temperature (20oC) and adiabatic condition for all walls.
Two methods are used to evaluate HTC; one is based on an isothermal simulation, where qw(iso) is wall heat flux and Tnw(iso) is near wall fluid temperature, and the other is based on combination of of adiabatic and isothermal simulations , where Taw is adiabatic wall temperature.
Figure 3a presents CFD predicted pin-fin wall HTC for different wall surfaces roughness of pin-fin and end-wall inside cooling passage.
Figure 3b presents CFD predicted Nusselt number at four different Reynolds numbers Red5=9000; 18000; 27000 and 36000.