Numerical Simulation And Optimization Of FSAE Racing Car Outflow Based On CFD

When the race car running on the road,reducing its resistance coefficient whileincreasing its negative lift have an important influence on the steering stability,accelerationperformance,braking performance and the cornering speed of the car.Therefore,increasing thenegative lift of the car in the aerodynamic design process has a critical impact on the overallperformance,Using computer-aided simulation software based on computational fluiddynamics simulation theory to simulate the car in the wind tunnel,and then optimizing thedesign of the car based on simulation results becomes more and more important.In this study,using a Formula Student race car as research object.Firstly,buildthree-dimensional model of the designed car in the three-dimensional softwaresolidworks.depending on the size of the car frame and related requirements,the car body, nosewing,tail,etc.1:1three-dimensional models are built.imported these3D models into ICEMCFD software to get suitable mesh,then imported grid file into Fluent software to simulate theexternal flow.In the optimization process,firstly,the exterior shape of race car was modifiedwith a evaluation criteria of low drag coefficient and high negative lift.For the nose wing andtail wing,after the cross-sectional shape were selected,parametric their wing attack angles andthen use the goal drive optimization method to determine the attack angles in different workconditions,at last,analysis the influence of the aerodynamics on the vehicle based on thesimulation results.After using software to simulate the flow chart and draw a body pressure contours ofracing car body,according to the figure,local optimization were made on the carbody;according to pressure contours of nose and tail,attack angles are optimized based ongoal-driven method,the kind of diffuser is chosen and the side box is processed depending onthe vehicle flow and pressure contours of the car body.Compared results before and after optimization simulation,drag coefficient of the carbody is reduced;proper attack angles of the nose wing have an important influence on thenegative lift;when the car running in different work conditions,changes in the attack angles of tail have great impact on the performance of tail wing;performance of the diffuser is affectedby the side box when it has limited position.