Aerodynamic Design And Optimization Of FSAE Racing Car Body

The rapid development of Students' Formula racing cars puts forward more stringent requirements on their performance indicators such as speed,fuel economy and handling stability.The excellent aerodynamic characteristics of racing cars are increasingly focused on and seen as a core influencing factor.Racing cars with good aerodynamic characteristics can not only reduce the impact of air resistance,but also can achieve better fuel economy and handling stability.Therefore,the body styling becomes a very important step in the entire R&D process of the car.At the same time,since the body styling of racing cars is a very complex and highly integrated procedure based on various related theories and R&D experiences,a set of high-quality and high-efficiency body design processes and methods for racing car is necessary to ensure the design quality.Started with a thorough study of the development history and the related theoretical knowledge of racing cars,a profound research on the racing car body design process and optimization methods is carried out in this thesis.First of all,based on the theoretical basis of the ideal body shape with excellent aerodynamic performance,the racing car body is designed according to its general layout design,and the body styling has been optimized by using air resistance coefficient and lift coefficient as design objectives.The main research work of this dissertation is as follows:1)Based on the existing theoretical knowledge,the digital model of ideal body shape is created,and analyzed by using CFD method;2)Starting from the ideal body shape,the racing car body styling is designed using CATIA,and the aerodynamic characteristics of the original 3-D digital model is simulated with CFD and the good aerodynamic performance of the initial body styling is obtained;3)In order to further optimize the body styling,the Sculptor software is applied to create a control body for the deformation of the body styling,and multiple control points for body deformation are set up and a couple of displacement variables of these control points are founded as the input variables for further optimization;4)By integrating the software of Sculptor and Fluent into the platform of Isight,and taking the air resistance and lift coefficients as the output variables,the parallel simulation of both software has been realized and the Sample data of input and output variables are acquired;5)Based on the above sample data,Isight's Approximation model is used to carry out the multi-objective optimization for the body styling of racing car,and the best optimization result is achieved,and then the optimal design are verified with the CFD simulation method and wind tunnel testing,and finally the results of both methods show their good consistency.From the research results of this paper,the racing car body design by using the ideal body shape as the base can mainly retain the excellent aerodynamic characteristics of the ideal body.The approximate optimization model with the input and output sample data from DOE can be used for multi-objective optimization of a specific racing body styling,which can not only reduces resistance and lift,but also improves design efficiency and greatly reduces huge optimization workload.The wind tunnel experiment research on the racing car body styling has further verified the correctness of the aerodynamic design process and its optimization method.The final optimization results of this paper show that the drag coefficient of the racing car body is reduced by 15.64%and the absolute value of lift coefficient is decreased by 23.49%.Therefore,this method can provide a certain guiding role for the body styling of the Formula Student racing car.