低压轴流风机周向弯曲叶片顶部间隙流动的数值分析

利用雷诺平均N-S方程组以及S-A一方程湍流模型对带有径向、周向前弯、周向后弯叶片的低压轴流风机在稳定工况点处进行了三维粘性流场的数值计算。在数值模拟结果与试验测量结果吻合的前提下，根据计算结果，分析了叶片吸力表面和压力表面在顶部的压力分布的特点，揭示了在叶顶到机壳壁面之间泄漏流的发展过程以及损失分布。对难以测量部分的数值分析，深入理解了叶片的周向弯曲大小及方向对顶部间隙流动和叶轮工作稳定性的影响，为进一步改进此类风机的设计提供了更充分的依据。图4表1参7

Numerical Analysis of Flow in Tip Clearances of Circumferential Bent Blades of Low Pressure Axial Flow Blowers

3 dimensional viscous flow fields,under steady operating conditions,of a low pressure axial flow blower,are being numerically calculated by using the Reynold's average N-S equation together with a S-A one-equation turbulence model,respectively for wheels fitted with twisted,circumferentially forward bend and circumferentially backward bent blades.According to numerical simulation results,which concur with experimental data,the specially featured pressure distributions at blade tips both on the suction and the pressure surface are being analyzed,disclosing the development process of leakage through the clearance between blade tip and casing,as well as the loss distribution.By numerically analyzing phenomena,hard to grasp by measurements,a deeper understanding has been attained concerning the effect,on blade tip leakage and on the wheel's operational stability,of circumferential bending of the blades in different directions.Advanced supporting material for designing similar fans is herewith being presented.Figs 4,table 1 and refs 7.