采用PIV研究轴流风机叶顶泄漏流动

将粒子图像测速技术(PIV,ParticleImageVelocimeter)应用到低速轴流通风机实验台上,在设计工况下对轴流通风机转子叶顶区域的瞬态速度场进行了实验测量。测量得到了三个不同周向位置下的涡量图和速度矢量图,并观测到了叶顶泄漏涡的涡旋结构。重点研究了叶顶泄漏涡位置的不稳定性和锁相平均后的叶顶泄漏涡涡心的轨迹,并将实验结果与原有模型进行了比较。结果表明:叶顶泄漏涡涡心的运行轨迹与现有模型得出的估算公式的计算结果接近,基本吻合。

The investigation of tip leakage flow of an axial fan by PIV

In this paper, the flow field in the tip region of an axial ventilation fan is investigated with the PIV system at the design conditions. The characteristic of the ventilation fan is an extreme low-pressure difference, a large tip clearance with a low rotating speed. The flow field was surveyed in three quasi-S2 planes, mainly focusing on the outer 90% blade span. The velocity vector and vortical contour in three different circumference positions were successfully acquired and the structure of the tip leakage vortex was clearly illustrated. In the paper, the unsteadiness of the leakage vortex and the position of the vortex were surveyed in detail. The center loci of tip leakage vortex at different times and the mean center loci of the leakage vortex were particularly displayed. Besides, the measurements are found to be in good agreement with existing models for the position of the vortex when appropriately interpreted.