摘要
汽车进出风口对汽车空气动力学特性有重要的影响。利用CATIA建立了三种不同进出风口的汽车模型,利用CFD方法研究不同进出风口对汽车流场的影响。采用三维不可压缩雷诺平均方程N-S方程采用RNG k-ε湍流模型,利用二阶迎风差分格式获得控制体积界面上的物理量,应用SIMPLEC算法进行迭代计算,对汽车流场进行模拟仿真,并将结果进行对比分析。研究结果表明:汽车前端只有一个进风口的情况下,发动机迎风面的高压区偏上,并且高压区的压力明显低于增加辅助进风口的情况。将三种情况下仿真得出的发动机舱内散热所需的冷却空气量与实际所需要的空气量对比,结果显示,汽车前端只有一个进风口的情况不能满足发动机舱内的散热需求,而其余两种情况能够满足散热需求。
Vehicle air inlet and outlet have an important influence on vehicle aerodynamic characteristics. The three car models with different air inlet and outlet are built using CATIA and their flow fields are studied by using FLUENT. The mathematical model is the average Reynolds equation of incompressible flow, and the turbulent model is RNG model. Its discretization scheme is second order upwind. It uses SIMPLEC to solve the discrete equations. In the case of only one in- let, the high pressure zone of engine upwind surface is upward, and the pressure is lower than the case of having assis- tant air inlet. The cooling air in the case of only having one inlet is less than the actual cooling air in need, and the other two cases are well done. The aerodynamic drag in the case of having assistant inlet is higher than that in the case of only having one inlet. The aerodynamic lift in the case of having outlet is lower than that in the case of having assistant inlet. The aerodynamics drag of the engine surface is increasing in the three models.
出处
《汽车科技》
2009年第5期38-40,48,共4页
Auto Sci-Tech
关键词
进风口
出风口
流场
数值模拟
汽车
air inlet
air outlet
flow field
numerical simulation
car
