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Using CFD method, contrast and analyse the annular identical-cross-section straight pipe and annular hyperbolically curved pipe, the calculation results prove the superiority of the hyperbolically curved pipe.
With the development of boundary layer theory and CFD, it has been able to achieve the computer numerical simulation of a variety of complex turbulent pipe flow velocity distribution.
Computational fluid dynamics simulation software CFD is adopted to create a smooth hole with low Reynolds number, fully turbulent binding simulation model.
∂(ρk)∂t+∂(ρkui)∂xi=∂∂xjμ+μtσk∂k∂xj+Gk-ρε-2μ∂k12∂n2 (1) ∂(ρε)∂t+∂(ρεui)∂xi=∂∂xjμ+μtσε∂ε∂xj+C1εkGkf1-C2ερε2kf2+2μμtρ∂2μ∂n22 (2) μt=Cμfμρk2ε (3) Numerical simulation of the Intakes flow field and results analysis The numerical simulation and flow velocity distribution in the Internal flow field.
[4] Wang Fujun: Computational Fluid Dynamics Analysis—CFD Software Principles and Applications (Tsinghua University Press, Beijing, 2010).

Numerical simulation method for aero-acoustics based on acoustics analogy shows some promise to CAA.
As a result of [13], the FW-H solver can now be integrated in the CFD solver and works in a parallel computing environment to provide a far field acoustic pressure prediction in line with the CFD near field prediction.
According to reference[17], the time-step (Dt) of 2×10-6 s was used for the transient simulation.
D., Simulation of supersonic cavity flow using 3D RANS equations, AIAA paper 2004-4966
Koutsavdis, A versatile implementation of acoustic analogy based noise prediction method in a general-purpose CFD, AIAA paper, 2003-3202.

The Analysis of Aerodynamic Load for High Speed Centrifugal Compressor Blade Zhu Guihua1,a, Qiu Tuanhui1,b and Xie Min2,c 1College of Mechanical and Electrical Engineering,Central South University,Changsha,P.R.china 2Valin Steel,Xiangtan, P.R.china azhuguihuaok@163.com,bqiutuanhui@163.com,cxm54289@sina.com Keywords: Centrifugal Compressor; Blade; Aerodynamic Load; CFD; flow rate Abstract: With the ANSYS Workbench software,the 3D fluid model of the impeller for the centrifugal compressor is set up,whose design flow is 3.2kg/s,rotating speed is 32473r/min,pressure ratio is 3.8,and then with the method of CFD,the k-ε two equations model is selected as the turbulence model,in the condition of design speed,the fluid region of the impeller is simulated under eight different flow rate,the aerodynamic load of the impeller blade and its distribution is acquired under different flow rate,the results showed that the location of the largest aerodynamic load is in the blade that near the outlet
method,then the aerodynamic load is studied. 1 Numerical simulation 1.1 Turbulence model The internal flow of centrifugal compressor is mainly affected by the pressure difference between the inside and outside wall, the centrifugal force of rotation, the curvature of the flow channel; it is a complex three-dimensional flow[5].
to simplify the model,A gap between the vane and the volute value is set to 0 for simulation.The mesh quality directly affect the stability of the numerical simulation of the process,convergence,speed and accuracy.Grid type selected as unstructured grid,Total 123952 nodes and 401204 units,as shown in Fig 2.
Fig 1 The impeller Fig 2 The fluid grid 1.3 Boundary condition Select the boundary conditions of the inlet total pressure and mass flow,the reference pressure is 1 atm,the total temperature and total pressure is given in the importing location,the mass flow is given in the experot location;set periodic boundary condition in the circumferential boundary of the impeller’s upstream and downstream extended aero.Set impermeable,no-slip and adiabatic wall boundary conditions for the solid wall in order to make the mass flux,momentum flux and the energy flux is zero,which is through the grid surface coincides with the solid boundary.The rotation speed is set to be 32473r/min, a temperature of 25℃ air was selected as the fluid medium,the high-level solving mode is selected as the solving format.The calculation convergence criterion is that RMS residual error is less than 1×10-5. 2 The CFD Simulation results and analysis 2.1 Relationship between the aerodynamic loads and
[8] Xie Longhan, Zhao Xinyu,Zhang Jiongming, ANSYS CFX Fluid analysis and simulation, beijing, Publishing House of Electronics Industry. 2012.

The diffuser potential field acting on the impeller has been studied using CFD by [19,20].
Zhao, Numerical simulations of stall inside a centrifugal compressor, Power and Energy IMechE. 221 (2007) Part A: J
Roger, Dougal, Dynamic centrifugal compressor model for system simulation, Journal of Power Sources. 158 (2006) 1333-1343
Flow simulation using control volumes of arbitrary polyhedral shape.
Peck, Validation of unstructured CFD modelling applied to the conjugate heat transfer in turbine blade cooling.

In this study, moving mesh technique is used to construct an outside flow CFD model around H-vertical axis wind turbine with different types of airfoil.
Numerical simulation method Equation.
Number the three blades of CFD model as yepian 1, yepian 2, yepian 3.
[2] Zhiqian Yang, Wenzhuan Cui: Numerical simulation for 2D unsteady flow around the vertical axis wind turbine (Modern Manufacturing Engineering, 2009)
[3] Congxin Yang, Faming Wu, Yuliang Zhang: Numerical simulation on unsteady rotated flow of a vertical axis wind turbine based on moving meshes (TRANSCATIONS OF THE CHINESE SOCIETY FOR AGRCULTURAL MACHINERY, 2009) [4] Ping He, Danmei Hu: The numerical simulation of offshore wind turbine (Renewable Energy Resource, V01.28 No.4 Aug.2010)

Furthermore, a computational fluid dynamics (CFD) simulation will be implemented to predict the mass flow rate of the prototype fuel injector.
Computational Fluid Dynamics Simulation Modeling of the CNG Conduit.
FLUENT Simulation Results.
The purpose of the CFD simulation was to determine the mass flow rate of CNG at the pressure outlet of the fuel injector.
Table 2: Assumptions for CFD analysis.

A three-dimensional numerical model was developed based on CFD software FLUENT to simulate leakage process of liquid ammonia tank.
Numerical simulation analyses 3.1 Diffusion characteristics The gas velocity vector on the Z=45m plane at t=10s shows in Fig.3.
Mochida: CFD prediction of gaseous diffusion around a cubic model using a dynamic mixed SGS model based on composite grid technique[J].
[5] Yoshihide Tominaga, Ted Stathopoulos: CFD modeling of pollution dispersion in a street canyon: Comparison between LES and RANS[J].
[8]TAN Wei, LIU Xiao, LIU Yu-jin, et al: Modeling the two-phase cloud evolution from instantaneous flashing release using CFD[J].

Study of high-pressure waterjet characteristics based on CFD simulation Liping Cao1,a, Shi Liu2,b,Yaosong Huang1,c and Qian Liu and1,d Zhihong Li1,e 1School of Power, Energy and Mechanical Engineering, North China Electric Power University, Beijing 102206, China 2School of Control and Computer Engineering, North China Electric Power University, 102206 Beijing, China aclp198@126.com, bliushi_ncepu@yahoo.com.cn, chys1986@126.com, dliuqian0607@163.com, elizhihong@ncepu.edu.cn Keywords: High-pressure water jet, flow field, axial velocity, dynamic pressure Abstract.
Fluent will be applied to the nozzle flow field numerical simulation, study the main physical quantities of the nozzle flow field distribution, and provide a reference for practical application.
Initially, the CFD model considers two-phase (air and water) flow, where air is treated as the primary phase.
Simulation results and analysis Velocity distribution of the nozzle flow field.
Flow field simulation and experiment of pre-mixed abrasive water jets outside the nozzle[J], Journal of China Coal Society, (2009), p. 410-414

According to the development of a new type of oil purifier——HIGEE rotating oil purifier, this paper has carried out related numerical simulations.
This paper has carried out numerical simulation using CFD software——FLUENT.
Modeling flow through porous media and multiphase flow are two main respects in the numerical simulation.
a1)150g b1)150g a2)300g b2)300g c1)500g c2)500g Fig. 3 Numerical simulations of different accelerations of gravity: 1) Contour plot of the volume fraction of oil; 2) graph of the outlet volume fraction of oil Fig. 3 displays the numerical simulations of different accelerations of gravity.
Conclusion Two-phase porous medium flow model in the RPB was built, and by using CFD software——FLUENT the distribution of the phases in the RPB which is on different conditions has been simulated.

Introduction The past 50 years have seen a revolution in the entire engineering design process as computational simulation has come to play an increasingly dominant part.
CFD simulations of wing shape have been reported [5, 6] in china.
Our numerical simulation model as followed in the figure 4.
The CFD is most important from this aspect, some countries make great effort has led to major advances.
Coakley.1987.Numerical Simulation of Viscous Transonic Airfoil Flows.