不同后倾角三维车辆的尾迹非定常流动分析  

Unsteady flow analysis for wakes of three-dimensional vehicles with different rear slant angles

作　　者：崔文诗[1,2] 杨志刚[1,2] 王国俊[1,2] 周华[1,2] CUI Wen-shi YANG Zhi-gang WANG Guo- jun ZHOU Hua(Shanghai Key Laboratory of Vehicle Aerodynamics and Vehicle Thremal Management System, Shanghai 201804, China Shanghai Automotive Wind Tunnel Center , Tongji University,Shanghai 201804 , China)

机构地区：[1]同济大学上海市地面交通工具空气动力与热环境模拟重点实验室,上海201804 [2]同济大学上海地面交通工具风洞中心,上海201804

出　　处：《吉林大学学报（工学版）》2017年第3期717-724,共8页Journal of Jilin University:Engineering and Technology Edition

基　　金："973"国家重大基础研究发展计划项目(2011CB711203)

摘　　要：为了控制车辆气动力和噪声,基于热线风速仪将流动与频谱法、相关分析方法结合,对不同后倾角(0°,25°和35°)的三维车辆尾迹非定常流动进行试验研究。0°模型主频数为2个,对应流向和侧向涡脱落作用;25°模型主频数为4个,对应流向涡脱落及其共振作用、C柱涡和斜背动态分离作用;35°模型主频数为3个,对应C柱涡和上、下流向涡脱落作用。结果表明,模型间存在差异的原因是后倾角的不同使得流动分离位置、斜背流动、C柱涡产生差异,进而导致主频数及其表征的非定常流动结构、空间分布规律不同。IN order to control the aerodynamic force and noise of ground vehciels, unsteady flows in the wake of three-dimensional （ 3D） vehicles with different rear slant angles （ 0% 25° and 35°） were experimentally studied with fluid dynamics, spectrum and correlation analysis for data processing, using hot wire anemometry. Two frequencies measured in the wake of 0° model are resulted from the unsteady flow emanating from the recirculation bubbles in the flow direction and the side direction respectively. Four frequencies detected for the 25° model are ascribed to C-pillar vortex, dynamics attachment flow on the rear slant, the structures emanating from recirculation bubbles in flow direction and resonance effect. Three frequencies captured for 35° model are connected to the structures emanating from the recirculation bubbles in flow direction and C-pillar vortex. The differences are significant among different models. Flow separation position, flow on the rear slant, C-pillar vortex are all different for different slant angle, which explains the physical meaning for each unsteady flow, the quantity and spatial distribution of dominant frequency.

关 键 词：车辆工程 非定常流动 尾迹 涡脱落 流动分离 

分 类 号：U467.1[机械工程—车辆工程]