基于改进LRNk-ε模型的汽车气动特性研究  

Research on Aerodynamic Characteristics of Vehicle with an Improved LRNk-ε Turbulence Model

作　　者：谷正气[1,2] 陈阵[1] 黄泰明[1] 丰成杰 宗轶琦[1] 

机构地区：[1]湖南大学汽车车身先进设计制造国家重点实验室,长沙410082 [2]湖南工业大学,株洲412007

出　　处：《中国机械工程》2015年第18期2550-2555,共6页China Mechanical Engineering

基　　金：国家自然科学基金资助项目(50975083);交通运输部新世纪十百千人才培养资助项目(20120222);"中国高水平汽车自主创新能力建设"资助项目;湖南大学汽车车身先进设计与制造国家重点实验室自主课题资助项目(734215002);财政部创新团队资助项目(0420036017)

摘　　要：针对由Jones和Launder提出的LRN(低雷诺数)k-ε湍流模型对转捩预测不足等问题,引入全应力限制(TSL)方法及流线曲率因子以改进湍动能耗散率及湍流黏性系数,最终获得了一种改进的低雷诺数湍流模型,并将其应用于汽车外部流场计算仿真中,利用ISIS-CFD求解器实现计算。将计算结果与其他常用于汽车外部流场仿真的湍流模型以及风洞试验得到的结果进行了对比分析,结果表明,在同等计算条件下改进LRNk-ε湍流模型能更加准确且高效地模拟车身表面的气流分离以及尾部流场。Since the LRN（low Reynolds number）k-ε turbulence model presented by Jones and Launder failed to predict the laminar-turbulent transition, the streamline curvature factor and total stress limitation（TSL） were incorporated to improve the turbulent dissipation rate and turbulence vis- cosity coefficient. Thus, a new modified LRNk-ε turbulence model was obtained for the prediction of the aerodynamic characteristics of vehicles. Computations were carried out using the ISIS-CFD flow solver. The comparisons among the results obtained by the modified LRNk-εmodel with ones by oth- er commonly used turbulence models and wind tunnel experiments show that the new model is more accurate and efficient to simulate the flow separation around the body surface and the wake vortexes.

关 键 词：湍流模型 转捩 汽车外流场 风洞试验 AHMED 

分 类 号：U461.1[机械工程—车辆工程]