定常喷/吸流动主动控制方法减阻研究

Study on drag reduction by active flow control with steady blowing /suction methods

摘要:

针对Ahmed类车体,在车身斜面选定位置处设置控制槽,采用证明为有效的大涡模拟数值方法,研究定常喷/吸流动主动控制方法的气动减阻机理及效果。基于流场数据分析,发现：喷射控制致使车体斜面上流动大分离发生,拖曳涡对得以消除,但尾迹区尺度增大,气动阻力上升；抽吸控制方法抑制和消除展向涡结构的产生及发展,但拖曳涡对未受显著影响,气动阻力下降。

关键词:Ahmed类车体;分离流动;流动主动控制;大涡模拟

Abstract:

Taking Ahmed body with flow control slot at special location of slanted surface for object, the mechanism and effect of steady blowing/suction methods belonging to active flow control concept were studied by using large eddy simulation that is proved accurate. Base on analysis of flow field data, the blowing control method results in fully separation on the slanted surface and enlarged recirculation zone around body with higher aerodynamic drag, although trailing vortex pair is eliminated. The suction control method eliminates and delays the production and development of spanwise vortices structure with lower aerodynamic drag, however trailing vortex pair remains unchanged.

Key words:Ahmed body;Separation flow Active flow control;Large eddy simulation