不同波长瞬态侧风对汽车气动性能影响分析

摘要/Abstract

摘要： 利用大涡模拟对某轿车受到的瞬态侧风进行研究，并采用自定义函数（UDF）控制边界的方法实现了正弦侧风在时间及空间上的瞬态变化，分析了三种不同波长的正弦侧风对气动力系数的影响，并将结果与风洞实验及稳态模拟的结果进行对比。结果表明：受到瞬态变化的正弦侧风时，气动力系数呈周期性变化，但气动阻力系数的变化频率是气动侧力及横摆气动力矩系数变化频率的两倍；瞬态正弦侧风波长减小时，气动阻力系数的变化范围逐渐减小；在瞬态侧风作用下，A柱对汽车的气动性能产生了重要影响。

关键词: 大涡模拟, 瞬态侧风, 波长, 气动力系数

Abstract: The large eddy simulation was used to investigate the vehicles subjected to transient sinusoidal crosswinds, and the transient crosswinds were changing in time and space, which was realized by the user defined function(UDF) to control the boundary conditions. The effects of the transient crosswinds with three different wave-lengths on the coefficient of the aerodynamic forces were analyzed, and the results were compared with the experimental and the quasi-steady simulation. The results show that: the coefficients of the aerodynamic forces are changing in periodic when the vehicles subjected to the transient sinusoidal crosswinds, but the change frequency of the coefficients of the drag forces is two times of the coefficients of lift and yawing moments. The changing range of the coefficients of drag forces are gradually decreased when the wavelengths of the crosswinds are reduced. The A-pillar has important influences on the vehicle aerodynamic performances in crosswinds.

Key words: large eddy simulation(LES), transient crosswind, wave-length, coefficient of aerodynamic force

中图分类号:

U469

黄泰明, 谷正气, 丰成杰, 陈阵. 不同波长瞬态侧风对汽车气动性能影响分析[J]. 中国机械工程.

Huang Taiming, , Gu Zhengqi, Feng Chengjie, Chen Zhen. Analysis for Effects of Transient Crosswinds with Different Wave-lengths on Vehicle's Aerodynamics Performance[J]. China Mechanical Engineering.

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