车尾水平收缩气动减阻的规律及机理

Regulation and mechanism of aerodynamic drag reduction by horizontal tail contraction

摘要:

以MIRA两厢车为对象，采用风洞实验和数值仿真方法，对气动阻力受车尾水平收缩的影响规律进行研究，表明车尾水平收缩提高尾部表面压力水平，有效降低气动阻力；基于可靠性被验证的数值仿真结果，对尾流结构变化规律进行研究，表明车尾水平收缩为尾部死水区提供额外动能，抑制拖曳涡对的形成和发展，减小尾迹区流动能量损失，降低气动阻力。

Abstract:

By wind tunnel test and numerical simulation, the regulation of horizontal tail contraction on aerodynamic drag reduction was studied. The results indicate that tail contraction raises pressure level of tail surface and reduces aerodynamic drag. Base on result of reliable numerical simulation, the changes of wake structure were studied. The research indicates that tail contraction provides additional kinetic energy for tail dead zone, suppresses formation and development of trailing vortex pair, reduces flow energy loss of wake and aerodynamic drag.