摘要
冲击射流广泛应用于短距、垂直起降飞行器(SVTOL)等航空航天领域,然而却伴随着流场与噪声等诸多方面的问题,笔者采用PIV(粒子图像测速)技术对超声速冲击射流的流场结构和涡结构进行了深入研究。实验发现在不同的冲击工况下,冲击射流流场结构呈轴对称和螺旋结构,其瞬时流场的主涡结构也有类似特征,脉动流场在瞬时流场主涡结构的基础上会附加与主涡旋转方向相反的次涡结构,在对称和螺旋两种模态下,由于涡结构的影响,冲击射流的近壁速度存在较强的脉动。
Impinging jets widely exist in many engineering fields, such as a short take-off and vertical landing （SVTOL） aircraft, as well as air nozzle etc. In this paper, vortex structures and flow patterns were studied by PIV （Particle Image Velocimetry） technique. Two flow modes were found out at different impinging cases, one is axisymmetric mode and another is helical mode. The flow modes may be caused by main vortex structures in instantaneous velocity field. In the fluctuating velocity field, there are second vortex structures with reverse swirling relative to the main vortex. For both flow modes, there are stronger fluctuation velocities near the wall, caused by vortex structures.
出处
《实验流体力学》
EI
CAS
CSCD
北大核心
2007年第4期32-35,共4页
Journal of Experiments in Fluid Mechanics
基金
国家自然科学基金(10572074)
