翼刀对双立尾/三角翼立尾抖振的影响

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

在北航的水槽和风洞中进行了加装翼刀的75°后掠双立尾/三角翼的立尾抖振实验,目的是研究翼刀对立尾抖振的影响。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翼刀对立尾抖振减缓的效果。流动显示的实验结果表明三角翼前缘涡涡核从翼刀上方经过时,会提前破裂,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28°到48°这段立尾抖振比较显著的迎角范围内,B1立尾位置的立尾抖振强度曲线比无翼刀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,频谱分析也能得到前缘涡提前破裂的结论,前缘涡的提前破裂起到了减缓立尾抖振作用。

Experiments of fences with twin vertical tails/delta wing of sweep angel 75°have been carried out in a water channel and a wind tunnel of BUAA in order to investigate effect of fences 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 vortices will breakdown early at the moment of the vortex core pass over the fences. Fences 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 2°to 48°） value of acceleration RMS curve of B1 position of vertical tails were distinct lower than curve with non-fences. The buffeting of vertical tails were diluted at certain angle of attack. And surface dynamic pressure signal RMS of tails were reduced by the fences. It is also found that the leading edge vortices will breakdown early by the power spectral analysis of pressure signal. The buffeting of vertical tails will be diluted at certain angle of attack by the leading edge vortices breakdown early.