基于URANS的Ahmed模型外流场分析  

Numerical analysis of external flow filed around the Ahmed model by URANS

作　　者：吴华杰 张善文[2] 张燕军[2] WU Huajie;ZHANG Shanwen;ZHANG Yanjun(Technology Research Center for Automotive and Parts Design and Manufacturing,Yangzhou University,Yangzhou 225127,China;School of Mechanical Engineering,Yangzhou University,Yangzhou 225127,China;Schoolof Mechanicaland AutoEngineering,YangzhouPolytechInstitute,Yangzhou225127,China)

机构地区：[1]扬州大学汽车及其零部件数字化设计与制造技术工程中心,江苏扬州225127 [2]扬州大学机械工程学院,江苏扬州225127 [3]扬州工业职业技术学院机械与汽车工程学院,江苏扬州225127

出　　处：《扬州大学学报（自然科学版）》2020年第4期54-59,72,共7页Journal of Yangzhou University：Natural Science Edition

基　　金：国家自然科学青年基金资助项目(51605424);江苏省六大人才高峰资助项目(JXQC-018);江苏省博士后基金资助项目(1501164B)。

摘　　要：基于URANS(unsteady Reynolds averaged navier-stockes)方法,采用标准k-ε湍流模型对Ahmed模型的外流场进行数值模拟.结果表明:网格划分对模拟结果产生较大的影响,故在对Ahmed模型外流场进行数值模拟时,需要进行严格的网格无关性分析;Ahmed模型外流场呈现周期性变化的瞬态特征,采用Q准则能够识别出流场中3个典型涡系;Ahmed模型底涡由流体脱离下表面时产生,并周期性地向下游输运,而角涡由尾部的倾斜段诱导产生.Based on the URANS method,the standard k-εturbulence model is used to simulate the flow field of Ahmed model.The results show that mesh generation has a great influence on the simulation results.Thus,strict mesh independence analysis is needed in the numerical simulation of the flow field of the Ahmed model.The flow field of the Ahmed model presents the transient characteristics of periodic change,and three typical vortices in the flow field can be identified by using the Q criterion.Further analysis shows that the base vortex is generated when the fluid is separated from the lower surface and transported downstream periodically,while the corner vortex is induced by the inclined tail section of Ahmed model.

关 键 词：汽车外流场 非稳态雷诺时均 Ahmed模型 计算流体动力学 涡结构 

分 类 号：TP391.9[自动化与计算机技术—计算机应用技术]