Research On Lifting Mechanism And Life Control Of Car Follow-up Tail

For high-speed vehicle stability and energy-saving emission reduction two issues,using automotive aerodynamics,establishing the physical model of the automobile tail,the mechanism and rule of the lift force control of the automobile tail are studied through the numerical simulation and a new type automobile tail which can control the lift and the lift direction can be constructed.the main content of the work is that:(1)The principle of generating lift was studied,and the two factors that produce the negative lift force are summed up.On the basis of this,the tail-wing angle of attack is used as a factor to find a kind of upper and lower symmetric airfoil with less resistance in the airfoil database.The simulation results of itself show that it can not only control the size of lift but also control the direction of lift,and its ability to produce positive and negative lift is the same.Finally,it was installed in the tail of the model car for joint simulation,to study its ability to control the lift in the car tail environment.It is found that when the angle of attack is positive,the ability to produce a positive lift decreased and the resistance increased;when the angle of attack is negative,the ability to produce a negative lift increased and the resistance increased.(2)Combined with the two factors of the wing to produce lift to construct a new high-performance tail,that is,front and rear symmetrical tail.And its performance and law of lift control are studied.It was installed in the rear of the car joint simulation to study the performance and law of tail to control the lift.Install the end plates at both ends of the front and rear symmetrical wing plate,and the effects of end-plate anti-tip vortices were studied,the actual application of the follow-up tail in regulating the lift of the car was illustrated.(3)Wind tunnel tests were performed on the vehicle and the front and rear symmetrical tail,although the experimental results and simulation results have a some error,it still can show that the front and rear symmetrical tail can control car lift.before the 30m/s the effect of rear wing control car lift is not very obvious,after it was 30m/s,the effect of rear wing control car lift is very obvious.