侧风状况下轿车气动特性的仿真与实验研究

Simulation and Experimental Study on Aerodynamic Characteristics of Vehicle in Cross-wind

以获得适合计算侧风气动特性的湍流模型为目的,应用计算流体动力学方法对比了标准k模型、RNG k模型、Realizable k模型以及SST模型对不同横摆角状态下轿车气动特性仿真结果的影响。结果表明,当0时,采用Realizable k湍流模型仿真得出的阻力系数与实验结果最为吻合,误差仅为1.53%,侧力系数的仿真结果与理论分析更为吻合;当3～1 5时,采用Realizable k湍流模型仿真得出的阻力系数与实验结果相比误差最大为0.96%,侧力系数的仿真结果与实验结果趋势一致,误差最大也仅为4.9%。总之,Realizable k湍流模型能够很好的模拟侧风状态下车辆的气动特性,仿真结果为进一步分析车辆的侧风稳定性提供了参考数据。

In order to find out the turbulence model,which was suitable for simulating the external flow field around a vehicle especially in crosswind,the CFD method was applied to compare the standard turbulence model,turbulence model,turbulence model and SST turbulence model,and these turbulence models were used for analyzing the aerodynamic characteristics of a vehicle in different yaw angles.The results show that： on the condition of,the drag coefficient of the simulation is most closed to the experiment data with the turbulence model,the most tolerance is 1.53%,and the side force coefficient is most closed to the result concluded by theory;on the condition of,the drag coefficient of the simulation is most closed to the experiment data with the turbulence model,the most tolerance is 0.96%.And the tendency of the side force coefficient accords with the experiment data,the most tolerance is 4.9%.Totally,compared to the others turbulent models,turbulence model is the most suitable one to analyze the aerodynamic characteristics of a vehicle in a crosswind,and the analysis of the results can provide a beneficial basis for vehicle＇s crosswind stability designing.