轴流风扇轴向间隙及尾迹恢复效应

利用非线性的谐波方法,采用数值模拟的手段,以Wennerstrom所设计的一台高载荷跨音轴流风扇级为例,对叶轮机械中著名的尾迹恢复理论进行了研究。当加大原设计的转、静子轴向间隙时,发现了与传统理论看似不一致的结果,即随轴向间隙加大了约30%静子弦长,风扇级的效率和压比都得到了提高。基于对转静子间非定长效应的详细仿真,并得出结论,尾迹在下游叶排中的湍流耗散效应在某些情况下会强于其尾迹恢复效应,同时轴向间隙的改变还会带来下游叶排进口速度三角形,叶排稠度等的改变,这些因素都会对压气机,风扇级的性能带来影响。以上研究补充和扩展了尾迹恢复理论。

Study on Wake Recovery Effect and Axial Space of Axial fan

The stage pressure ratio and isentropic efficiency were both found improved by increasing axial space by 30% of stator chord on a highly-loaded transonic axial flow fan stage,which seems contradictory to the traditional theory of Wake Recovery.Non-linear harmonic methodology was employed here for the simulation of rotor-stator unsteady interaction in order to investigate this phenomenon.It was found that in axial flow compressor/fan stages,the turbulent dissipation of rotor wakes strongly increased within d...