空气阻力及升力对高速车辆操纵稳定性的影响

Influences of Aerodynamic Drag and Lift on Handling Stability of High Speed Vehicle

建立考虑空气阻力及升力影响、前轮回正的车辆转向运动的动力学模型,求取考虑空气阻力及升力的车辆稳态横摆角速度增益。基于车辆稳态横摆角速度增益解析表达式,定量解析了空气阻力及升力对车辆转向特性的影响,得知随着车速提高,空气阻力及前轴处的空气升力增强,车辆不足转向趋势愈加明显,而后轴处空气升力的作用与前二者相反。基于上述车辆转向运动的动力学模型,通过数值仿真研究了空气阻力及升力对高速车辆路面不平度稳定性的影响,得知空气阻力及前轴处空气升力的增大可使车辆质心侧向偏移量减小,而后轴处空气升力的增大则使车辆质心侧向偏移量变大。

The steering dynanfics model considering influences of aerodynamic drag and lift, and front axle selfaligning was established. The corresponding expression of vehicle steering gain was induced. Steering characteristics of high speed vehicle was analyzed quantitatively,and the vehicle understeer tendency was strengthened by aerodynamic drag and air lift in front axle, air lift in rear axle did on the contrary, role with velocity increasing. According to the steering dynamics model, the influences of aerodynamic drag, air lift in front and rear axles on pavement irregularity stability of high speed vehicle were researched quantitatively by simulation. It is shown that its pavement irregularity stability was improved with increasing of air lift in front axle and aerodynamic drag,but with increasing of air lift in rear axle,its role is contrary.