汽车相会时外流场数值仿真分析  

Numerical Simulation Analysis of External Flow Field of Cars at the Moment of Passing

作　　者：何忆斌[1,2] 陈建美[1] 刘孟祥[1] 

机构地区：[1]湖南涉外经济学院机械工程学院,湖南长沙410205 [2]湖南大学汽车车身先进设计制造国家重点实验室,湖南长沙410082

出　　处：《机械与电子》2013年第7期7-11,共5页Machinery & Electronics

基　　金：湖南省科技计划资助项目(2012SK3171);湖南省自然科学基金资助项目(13JJ5038)

摘　　要：在进行汽车相会的气动特性变化对汽车操控性能的影响研究时,由于存在多相来流的影响,使用风洞和道路等传统试验方法是很困难的。如果将相会过程分成许多相等的时间片段,然后使用CFD对这些时间片段进行数值模拟,就可以得到外流场近似的计算结果。基于这一方法,对箱型汽车超车和迎面会车的2种相会情况下,基于时间片段的外流场变化,通过运用有限体积法求解三维、定常和不可压N-S方程,进行了数值模拟计算,得到了汽车流谱和表面压强分布以及侧向力系数的模拟计算结果,并对相应情况下的气动特性进行了初步分析。通过将汽车侧向力系数随着车与车之间相对距离变化的结果与实际试验结果对比,具有较好的一致性,从而验证了模拟计算方法的可信性。In the course of study on aerodynamic change and its effect on steering stability and controllability of automobiles in passing, due to multi interaction streams, it is difficult to use traditional methods, such as wind tunnel test and road experimental methods. If the process of passing a vehicle is divided into many time segments, and the segments are simulated with computational fluid dynamics （CFD） method, then the approximate computational results about external flow field will be obtained. Based on the idea, numerical simulation analysis of side force eoefficient of wagon - shaped car at the moment of passing, and preliminary discussion of aerodynamic characteristics of correlative situations are presented in the paper,by means of dividing the passing process into many time segments and then simulating external flow field of every time segment through solving threedimensional, steady and uncompressible N -S equations with finite volume method, this avoids the use of moving mesh, which takes large calculation resource and CPU processing time in calculating. Finally, the result of the side force coefficient of car is presented and coincident well with the experi- mental data, which shows creditability of numerical simulation methods presented in the paper.

关 键 词：外流场 相会 数值模拟 侧向力系数 

分 类 号：U461[机械工程—车辆工程]