尾缘锯齿结构的降噪物理机制实验

对比分析了常规尾缘翼型与锯齿尾缘翼型尾缘湍流流场的基本特征,并通过线阵列的方法测量了两种尾缘结构的噪声.结果表明:锯齿尾缘翼型尾缘湍流流场的湍流强度以及3个方向上的湍流强度都相比于常规尾缘翼型有显著减少,声场结果显示锯齿尾缘翼型对尾缘噪声有显著减小,对前缘噪声影响很小.锯齿结构加宽了尾迹区域并加快了大涡的破碎,产生了额外的马蹄涡,湍流脉动衰减率沿着流动方向变大. 

Experiment on noise reduction physical mechanism of serrated trailing edge structure

Basic characteristics of wake turbulence flow field of airfoils with serrated trailing edge and straight trailing edge were comparatively analyzed, and noise of two trailing edge structure was measured through line array method. The results show that the turbulence intensity of wake turbulence flow field and turbulence intensity in three directions of airfoil with serrated trailing edge are significantly reduced compared with airfoil with straight trailing edge. The noise field results show that trailing edge noise has a huge decrease on airfoil with serrated trailing edge, while the leading edge noise is nearly the same. Serrated structure widens the wake region and accelerates the breakdown of large vortex, resulting in additional horseshoe vortex. Turbulence decay rate along the flow direction becomes larger.