汽车外流场数值仿真中的湍流模型分析与应用

摘要

采用较为合理的计算流体力学分析技术对汽车高速行驶时其外部气动特性进行研究．以带有轮胎、侧后视镜以及天线等突出部件的某轿车外流场模型为研究对象，在稳态下采用RNS法中Realizable κ-ε两方程湍流模型结合增强壁面函数法对不同车速工况下整车外流场进行数值仿真计算．研究表明：沿车辆X纵向上所形成压力差是产生气动阻力的主要原因；随车速的提高，气动阻力的增长速度快于气动升力的增长．%A more reasonable computational fluid dynamics （CFD） analysis is carried out for the external aerodynamic characteristics of the high-speed car in this paper. The realizable κ-εturbulence two equations model of RNS methods based on the FVM （finite volume method） combined with the enhanced wall treatment method is apllied to simulate the external flow field of a car model with tires, side mirrors and antenna and other protruding parts under vehicle＇s different speed conditions. The results show that the difference of the vehicle surface pressure along the x-direction leads to the car＇s aerodynamic drag; with the increased vehicle＇s speed, the car＇s aerodynamic drag grows faster than the aerodynamic lift.