鼓包对双立尾/三角翼立尾抖振的影响

为了研究鼓包对立尾抖振的影响,在北航的水槽和风洞中进行了在机翼头部放置了鼓包的75°后掠双立尾-三角翼的立尾抖振实验,采用了流动显示、立尾表面动态压力测量、激光测立尾顶部加速度的实验来检验鼓包对立尾抖振减缓的效果。流动显示的实验结果表明三角翼机翼头部加上鼓包后,前缘涡涡核会发生弯曲和扭转,这在一定程度上减弱了前缘涡。激光测立尾顶部加速度实验的结果表明,在25°到48°这段立尾抖振比较显著的迎角范围内,A1立尾位置的立尾抖振强度曲线比无鼓包的曲线数值上有明显的减小,抖振得到一定的改善。立尾表面动态压力的脉动强度也有明显的减小,前缘涡涡核的弯曲和扭转起到了减缓立尾抖振的作用。

Effect of bulges on vertical tail buffeting of twin vertical tails/delta wing

Experiments of bulges with twin vertical tails/delta wing of sweep angle 75° have been carried out in a water channel and a wind tunnel of BUAA in order to investigate effect of bulges on vertical tail buffeting.The improved effects of vertical tails buffeting were examined by the experiments of flow visualization,unsteady pressure measurement on the surface of vertical tails and laser acceleration measurement on the top of vertical tails.The result of flow visualization experiment shows that the leading edge vortex core will be twisted and turned after bulges have been installed at the head of delta wing.Bulges were used to reduce strength of vertex breakdown.The result of laser acceleration measurement on the top of vertical tails experiment shows that at the angle of attack ranging with evident vertical tail buffeting（from 25° to 48°） value of acceleration RMS curve of A1 position of vertical tails is distinct lower than curve with non-bulges.The buffeting of vertical tails is diluted at certain angle of attack.And surface dynamic pressure signal RMS of tails is reduced by the bulges.The buffeting of vertical tails will be diluted at certain angle of attack due to twist and turn of the leading edge vortex cores.