Research Of SUV Aerodynamic Drag Reduction And Optimization Based On The Air-dam Of The Front Wheel

Automotive air dynamic performance, especially the aerodynamic drag characteristics, is one of the important properties in the research and development of automotive products. In order to carry out the aerodynamic drag reduction of the SUV, the square back MIRA model was used as the research object with the method of computational fluid dynamics. Several different structures of the front stop plate were established, one of the best reducing drag effect was selected, and the structural optimization was carried out with the parameter control. Finally, the optimized scheme was applied to the SUV model which reduced the aerodynamic drag of the vehicle.In addition, the flow state of the air flow around the other side of the Mira model is described, and the numerical simulation is carried out based on the understanding of the physical phenomena. In this paper, we choose the rectangular shape computation domain, which can guarantee the accuracy of the calculation and the efficiency of the calculation. The generation method of the grid is also explored. The grid transition is more uniform and can improve the accuracy of the calculation results. The linear growth mode will make the number and uniformity of the grid to achieve better coordination.The structure optimization, using ISIGHT integration sculptor and fluent, using DOE(design of experiment), with the optimization of the Latin method establish sample points; RSM with response surface method and Kriging model respectively before fitting choke plate structure variables and the wind resistance of the parameters of the response surface, combined with multi Island genetic algorithm in response to find the optimal solution, find the drag parameter minimum of choke plate structure; by analyzing and optimizing precision that best before choke plate structure. In this paper, the optimum structure of the front stop plate was applied to a real SUV model. Through the several simulations, the aerodynamic drag was effectively suppressed and the flow field structure of the vehicle was effectively improved.Through the research of this paper can provide reference for the numerical simulation of this kind of vehicle. At the same time, the design method of the orthogonal test design method is reasonable, and the change trend of the aerodynamic performance of the front stop plate is obtained, which provides a reference for the further research.