旋转导叶风机的理论分析与试验研究

本文应用叶轮机械叶片绕流控制的气动理论与边界层理论提出的旋转导叶风机,使设置在工作轮叶片表面上的附加导叶给边界层内气流增添了动量,改善了沿叶面的流速分布,从而避免了在临界与超临界工况下的边界层分离.对比试验研究表明,和不带导叶的同一台风机相比,这种旋转导叶风机在效率、噪声与工况范围等气动性能方面均有改善.内部流场可视化试验表明,设置于叶尖的导叶明显减少了叶尖间隙的反向流动与二次涡流,使出口流场更为均匀.

Theory Analysis and Experimental Investigation on Fans with Rotating Guide

A new type of fan with rotating guide is developed. The aerodynamic theory for turbomachines with encircling control along blade surfaces and the boundary layer theory have been used. Additional guide vanes on blade surfaces are provided to help increase the airflow momentum in the boundary layer and the velocity distribution on blade surfaces are improved. The separation of the boundary layer can be avoided even under critical or supercritical working conditions. The experimental results show that, compared with the conventional axial fan, the new one proposed in this paper is of higher efficiency and lower noise and with a greater range of stable operation. Flow visualization studies reveal that the small guide vanes on the rotor tip reduce the reverse flow through the tip clearance and abate the tip vortex. This contributes to the reduction in noise and more uniform velocity distribution at the guide fan exit. Theoretical analysis results are in agreement with test ones.