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Numerical Simulation Method for 3D Low Speed Micro Flapping-Wing with Complex Kinematics Wenqing Yanga, Bifeng Songb, Wenping Songc, Zhanke Lid and Yafeng Zhange School of Aeronautics, Northwestern Polytechnical University, Xi’an, 710072 China ayangwenqing@nwpu.edu.cn, bbfsong@nwpu.edu.cn, cwpsong@nwpu.edu.cn,dlizk@nwpu.edu.cn, eyawind@nwpu.edu.cn Keywords: CFD, flapping-wing, low speed, complex kinematics Abstract.
A numerical simulation method is presented in this paper for 3D low speed micro flapping-wing with complex kinematics.
The numerical simulations of solving Reynolds Averaged Navier-Stokes equations are used more and more in the flapping wing research for its high precision.
Lin [3] developed a 3D Euler/Navier-Stokes solver for simulation plunging/pitching NACA0014 airfoil.
The chimera system used in flapping-wing simulation is shown in Fig. 1.

Numerical Simulation on Ventilation Effect of Train-induced Wind in Subway Weichao Yang1,a, Limin Peng1,b, Chenghua Shi1,c and Zilin Hu2,d 1 Department of Civil Engineering, Central South University, Changsha 410075, Hunan, China 2Guangzhou Metro Design and Research Institute, Guangzhou 510010, Guangdong, China aweic_yang@163.com, blmpeng@csu.edu.cn, ccsusch@163.com,d30061417@qq.com Keywords: Subway, Piston air, Ventilation, Aerodynamic effects Abstract.
Yuan and You obtained the velocity and temperature field of a subway station and the optimized ventilation mode of the subway side-platform station by using CFD simulation [8].
Simplified simulation method The vehicle geometry is simplified for the computations by neglecting surface and underside details such as doors, windshield wipers and such mechanical parts as wheels sets, bogies, and so on.
J., CFD simulation and optimization of the ventilation for subway side-platform.
P., Numerical simulation for optimizing the design of subway environmental control system, Building and Environment 37 (2002) 1139–1152

According to the main results [6], based on experimental data and Computational Fluid Dynamics (CFD) studies, it was concluded that it was possible to combine in a single device, high separation efficiencies with low Euler numbers (Eu).
According to experimental studies and CFD simulations, it was found that the filtration associated with the hydrocycloning was a beneficial phenomenon, because it decreased the Euler number and the cut size diameter (d50), when compared to the conventional H11, under the same operating conditions.
The experimental results of Euler number for hydrocyclones H11-A and H11-B are consistent with the predictions [12], made from the CFD techniques.
Such behavior is in agreement with the CFD literature predictions, which showed that a rotating feed suspension could reduce the tangential velocity gradients within the hydrocyclone, responsible for the separation of a significant portion of particles.

Numerical Simulation Model of Hydrostatic Center Rest.
Three-dimensional geometry model of the oil film of two oil pads is introduced into the pre-processor of ICEM CFD to generate mesh.
The static pressure and the total pressure are computed numerically by using ICEM CFD.
When spindle rotating speed is 510r/min and carrying pressure is 2.1MPa, the relationship curve between lubricating oil dynamic viscosity and lubricating oil film dynamic pressure of heavy constant flow hydrostatic center rest can be obtained by using ICEM CFD, which is shown as Fig. 10.
In order to study the influence of inlet flow rate on the oil film dynamic pressure of heavy constant flow hydrostatic center rest, the inlet flow rate is assigned respectively 0.14kg/s, 0.16kg/s, 0.18kg/s, 0.2kg/s, 0.22kg/s, 0.24kg/s, 0.26kg/s and 0.28kg/s, and lubricating oil film dynamic pressure is computed numerically by using ICEM CFD.

Computational Fluid Dynamics (CFD) was used to analysis flow state and sine camber of tube influence on the heat transfer and flow, a correlation equations of Nu (Nusselt) =f(Re) is given.
Based on the above research background, this paper applied computational fluid dynamics (CFD) technology in research of convective heat transfer and flow resistance characteristics in sinusoidal corrugated tube.
Fluent, the commercial software of CFD was used to simulate the convective heat transfer and flow resistance characteristic around sinusoidal corrugated tube with different sine camber e.
(5) Numerical simulation and the theoretical analysis with field synergy principle indicate that the effect of field synergy is poor in the smooth tube, which is opposite to that in sinusoidal corrugated tube.

Numerical simulation.
The numerical simulation was performed using FLUENT, a commercial computational fluid dynamics (CFD) code, to compare simulation results to the test data.
Simulation model Fig.1 shows the dimensions of one heat regenerator used in a HiTAC regenerative burner.
Fig.1 shows the three-dimensional zone in the simulation.
In this study, all residual errors of the degree of freedom were set by , which is satisfactory for simulation analysis.

Simulation and Discussions In this section we use ESI-CFD+ software package for simulation.
(a) Pressure simulation result.
(a) Pressure simulation result.
(a) 2D simulation result.
(b) 1D simulation result.

In the present work, a computational fluid dynamics (CFD) model, based on the micromixer geometry and experimental conditions proposed by Ahmed et al. [3], has been used to numerically investigate the micromixing enhancement by ultrasonic vibration.
Theory and background The numerical simulations were performed using FLUENT.
The direct simulation method consists in solving the complete Navier-Stokes equations via the simulation software without making any assumption for each time step.
Thus the major disadvantage of this direct simulation method is very costly in computer time.
This flow pattern has been perfectly reproduced by the numerical simulation (Fig.4 (b)).

The accuracy of inclusion motion simulation was determined by the turbulence model and boundary condition.
Solution Procedure The CFD software CFX was used to solve the continuity, momentum, and turbulence equations.
Results and Discussions Computer simulation result.
Comparison of simulation result and experiment result.
And the simulation result was compared with the experiment result to evaluate its reasonability.

Investigation of Flow and Heat Transfer Characteristics of Annular Impinging Jet Watchara Musika1,a, Makatar Wae-hayee1,b, Passakorn Vessakosol1,c, Banyat Niyomwas1,d and Chayut Nuntadusit1,e* 1Energy Technology Research Center and Department of Mechanical Engineering, Faculty of Engineering, Prince of Songkla University, Hat yai, Songkhla, Thailand apop_ts@hotmail.com, bwaehahyee@gmail.com, cpassakornv@hotmail.com, dbanyat@engineer.com, echayut@me.psu.ac.th Keywords: Impinging jet, Annular jet, Heat transfer enhancement, CFD Abstract.
The numerical simulation was carried out to visualize the flow behavior.
Numerical Simulation Flow characteristics of the impinging jet were reviewed by using computational fluid dynamics software (ANSYS ver.13.0, Fluent).
Fig. 2 Nusselt number contours on impingement surface (Experimental results, Re=20,000, Tj=27oC) Fig. 3 Distributions of local Nusselt number on the impinged surface passing the centre of impingement region (Experimental results, Re=20,000, Tj=27oC) Fig. 4 (a): Distribution of Y-component velocity on centerline of impingement region above from the surface of 1 mm, and (b), (c): streamlines of jet on Z-X plane passing center of nozzle (CFD results, Re=20,000).