车模比例和风洞截面对轿车气动性能影响

采用三维不可压缩N-S(Navier-Stokes)方程和RNG k-ε(renormalization group k-ε)湍流模型仿真计算汽车流场特性.控制界面的物理量应用二阶迎风差分格式获得,并运用SIMPLEC压力修正法进行迭代.选用不同车模比例和风洞截面形状进行仿真计算,分析了车模比例和风洞截面形状对轿车气动性能的影响.结果表明:车模比例在一定范围内,汽车气动参数变化平缓;选用不同的车模比例在三种典型风洞模型中进行仿真计算,结果相差很大. 

Effects of car models proportion and wind tunnel cross section on aerodynamic characteristics of car

In consideration of the flow field characteristics of car aerodynamics, three-dimensional incompressible Navier-Stokes equations and RNG k-ε (renormalization group k-ε) model were used in simulation. Second-order upwind difference scheme was applied to obtain the physical quantities of control pedal, and SIMPLEC method was adapted for iteration. Different car model proportions and wind tunnel cross sections were simulated, the effects of car models proportion and wind tunnel cross section on aerodynamic characteristics of car were analyzed. The results show that: in a certain range of car models proportion, aerodynamic parameters of car changes gently; the simulation results of different car model proportions in three typical wind tunnel models vary greatly.