某SUV底盘空气动力性能优化研究OACSTPCD

Optimizing the aerodynamic performance of the vehicle chassis has an important impact on reducing the aerodynamic drag and lift of the vehicle.The optimized design in the chassis area is a crucial approach to improve the fuel economy and power of the vehicle.In this paper,a Computational Fluid Dynamics(CFD)simulation analysis of the external flow field is conducted for a sport utility vehicle(SUV).The paper compares the simulation accuracy of Realizable k-ε and SST k-ω turbulence models,ultimately selecting the Realizable k-ε turbulence model for the aerodynamic design of the chassis.Combining the SUV chassis characteristics and the flow field analysis,and aiming to minimize the overall cost,the paper designed five aerodynamic proposals for the chassis,including the front lower spoiler,the front wheel baffle,the sub-frame rear spoiler,the middle chassis guard and the tail muffler shape optimization.A full-scale wind tunnel test was carried out to verify the CFD simulation results.The results show that all five chassis proposals contribute to the improved aerodynamic performance. The tail muffler shape optimization has a notable impact on drag reduction, decreasing the vehicle's drag coefficient by 2.99％. When the five proposals are combined, the drag coefficient and lift coefficient are reduced by 5.16％ and 21％, respectively. The study effectively achieves energy-saving and drag reduction, and improves driving stability of the vehicle.