基于CFX的方程式赛车绕流场分析与优化

Analysis and Optimization of a Formula Racing Vehicle's Flow Field Based on CFX

针对某型大学生方程式(FSC)赛车的整车绕流场展开计算流体力学(CFD)分析与优化.利用三维建模软件CATIA对车身、车架、发动机总成、车轮及舱内模型进行建模、装配并生成风洞分析模型.采用集成于ANSYS Workbench环境下的流体分析软件CFX对此模型进行仿真分析,着重分析了赛车在正面风向状态下的受力情况及气流流态.仿真计算结果显示,原型车风阻较大,多处流场存在明显的紊流,影响了气动性能及赛车的速度性;气动升力及纵倾力矩偏大,影响赛车的驾驶稳定性.根据原型车的仿真结果,对车身及其他部件的优化改进提出几种策略,通过CFX仿真计算得出其优化效果.在对各项策略的优化效果进行详细分析后,通过选择优化效果好的策略、剔除无作用甚至反作用的策略以及多策略组合的办法,完成对原型车的优化设计.优化后赛车的气动性能得到提升,整车的气动阻力、气动升力及纵倾力矩均得到改善.

The analysis and optimization of computational fluid dynamics （CFD） are done for the flow field of a certain type of Formula Student China （FSC） racing vehicle .The body ,frame ,engine as-sembly ,wheels and cabin model are built and assembled by 3D modeling software CATIA ,and then a wind tunnel model is generated for analysis .The fluid analysis software CFX integrated in ANSYS Workbench is adopted for simulation .The stress and flow pattern when the wind blows frontally are mainly analyzed .The simulation results show that the prototype has large wind drag and there＆#39;re tur-bulences in fluid field ,w hich decreases the aerodynamic performance and the speed of the vehicle ;the aerodynamic lift and trim moment are too large ,which decreases the car＆#39;s driving stability .According to the results ,several optimization strategies are proposed and simulated through CFX .After these simulations ,the final optimization of prototype is completed by selecting useful strategies ,excluding useless or even counterproductive strategies and adopting multi-strategy method .Through optimiza-tion ,the aerodynamic performances including wind drag ,aerodynamic lift and trim moment are im-proved .