基于非光滑表面与涡流干扰的车身气动减阻方法

探讨了将表面非光滑形态结构减阻思想与流场主动控制相结合的车身气动减阻方法。将凹坑型非光滑表面布置在MIRA直背式模型的尾部，并在非光滑形态模型的基础上，在凹坑阵中加装喷射速度可变的涡流发生器来控制模型的尾部气流，改善尾涡结构。通过对光滑、非光滑、非光滑加涡流喷射三种模型的三维流场数值模拟，得到不同尾部形态模型的气流速度、压力以及湍动能等参数，对比不同风速下不同模型气动阻力系数的差异以及不同喷射速度下的减阻效果，分析模型尾部流场参数的变化，阐述了非光滑形态车身气动减阻机理以及涡流喷射扰动效应。研究结果表明：通过对非光滑形态被动减阻与涡流喷射主动减阻的优化组合，能有效地减少不同风速下直背式MIRA模型的气动阻力。

Aerodynamic Drag Reduction Method of Vehicle Body Based on Non-smooth Surface and Vortex Interference

 A body aerodynamic drag reduction method was discussed by combining the non-smooth surface morphological structure with active control of the flow field.Decorating pit type non-smooth surface on the vehicle rear end of MIRA straight back model，and on the basis of the non-smooth model，a vortex generator with variable jet velocity was equipped in the pit array to control rear air flow of model, improving the trailing vortex structure. Through three models' (smooth model, non-smooth model, non-smooth model with eddy injection) numerical simulations of three dimensional flow field，some parameters（such as airflow velocity, pressure, and the turbulent kinetic energy） of the models with different tail morphological characteristics were obtained， the difference of aerodynamic drag coefficient of different models under different wind speeds and the drag reduction effects under different jet velocities were compared. Changes of tail flow field parameter were analyzed, aerodynamic drag reduction mechanism and the effects of eddy-jet agitation of non-smooth body were elaborated.Results show that through a optimized combination which consists of passive drag reduction of the non-smooth form and active drag reduction of the eddy effusion, the aerodynamic drag of MIRA straight back model is effectively reduced.