车身外流场数值模拟

Numerical Simulation of Outer Flow Fields for Car Body

对某轿车车身的外流场进行了数值模拟,并分析了后风窗斜度对车身空气动力性能的影响。采用Hyper-mesh得到高质量的流场计算网格,运用Fluent求解计算,得到流场的CFD分析数据。利用HyperMorph实现车身网格的变形,在此基础上分析后风窗斜度对车身空气动力性能的影响。结果表明,小斜背的阻力系数较小;不是所有斜背汽车在后风窗斜度为30°时都会出现气动阻力系数峰值现象。本文所介绍方法可以应用于汽车的空气动力学设计,完善汽车的空气动力性能。

The outer flow fields of a car body are numerically simulated in Fluent and the influence of the slope of the rear windshield on aerodynamic property is analyzed.The grid of the flow field is got in HyperMesh,the simulation problem is calculated in Fluent,and the CFD data of the car is obtained.The slope of the rear windshield is changed by using HyperMorph and the influence of that on aerodynamic property is analyzed.The result shows that the cars with smaller slope of the rear windshield have smaller drag factor,and not all of cars with inclined back reaches the peak of drag factor when the slope of the rear windshield is about 30°.This study is beneficial to designing car bodies and improving the aerodynamic property of cars.