Coupling Study Of Body Position And Aerodynamic Characteristics Of Formula Racing

The World Formula One Championship is held by the International Federation of Automobile Sports(FIA).It is the highest level of the annual series of venues racing and the highest level of racing in the world today.With the continuous development of racing events and the continuous progress of computer simulation technology,in the case of relatively stable engine development,the teams will turn their attention to small changes in the car body,such as the installation of an airfoil,which will cause great changes in the aerodynamic characteristics of the vehicle,such as lift coefficient,pitch moment,and improve the acceleration level and driving stability.This makes the researchers pay more and more attention to the aerodynamics of the racing car,and invest more and more in the research and development cost and personnel.Because the shape of the racing car is different from that of the mass-produced car(for example,the former is the open wheel type),the emphasis of Aerodynamics Research and optimization is different.For example,the research and development of the F1 racing car pays the most attention to the lift of the whole car,while the main components affecting the lift are the front wing,the rear wing,the bottom diffuser and so on.This makes the R&D team devote more energy to the R&D of these components,while mass-produced vehicles pay more attention to drag reduction.At present,the domestic research on F1 racing car mainly focuses on the static aerodynamic characteristics of the car body while its attitude remains unchanged,while the research on the car body keeping motion is less.The research on the foreign racing team is more detailed and in-depth,but due to the confidentiality,the research data on the car aerodynamics are less published.This paper simulates and analyses the common motion conditions of a Formula 1 racing car,such as uniform motion and cross-windaffected motion,so as to keep the body moving continuously.At the same time,the suspension system is established to combine the body with the rotating wheel to simulate the racing car more truly,and the body posture and aerodynamic characteristics under several conditions are analyzed.In this paper,F1 racing car is divided into three parts: body(front wing,rear wing,bottom diffuser,body),suspension and wheel.By locking three degrees of freedom,body motion is limited,so that the body only keeps pitching,roll and vertical translation motion,while giving the wheel the same speed of rotation.Through simulation calculation,the data of surrounding flow field,body position and aerodynamic parameters of main components,such as ambient pressure field,velocity field,height of body off the ground,lift force,pitch angle and resistance of each component,are obtained under the condition of uniform motion and cross-wind motion.The data obtained from these transient calculations are compared and analyzed.When designing and optimizing the open-wheel racing cars such as Formula 1 racing car and University Formula racing car,with the increase of vehicle speed,we should focus on optimizing the lift fluctuation frequency,especially reducing the lift fluctuation frequency of the front wheel,and improving the flow of its rotation motion at the rear wheel position,which is one of the main difficulties in the downward pressure optimization.The front and rear wings,which provide the greatest downward pressure,are also the components with the greatest downward pressure fluctuation,so they are also the most important parts in the design of racing cars.The optimization of drag reduction in racing car should focus on the wheels,but it needs to improve the flow field through the optimization of other components.Compared with other components,the optimization design of diffuser can achieve the coexistence of drag reduction and increased downward pressure.When the pressure under the vehicle is larger,the body position is lower,the pitch angle is larger,and the clearance of the front wing is smaller.Under the action of cross-wind,the lower pressure of the vehicle decreases gradually,while the lift fluctuation frequency of the diffuser increases gradually.Therefore,the influence of cross-wind should also be taken into account in the optimization design of the diffuser.The drag reduction in the presence of crosswind should also focus on the wheels.The main reasons for the great change of the lower pressure are the change of the flow field of the bottom diffuser and the change of the attack angle of the rear wing caused by the existence of cross-wind.