周向弯曲方向对NACA65翼型轴流叶轮叶顶间隙流动影响  

Influence of the Bending Along the Circumferential Direction on the Flow in the Blade Tip Clearance in an Axial Flow Impeller Adopting the NACA65 Airfoil

作　　者：颜培弟 金光远 崔政伟 

机构地区：[1]江南大学机械工程学院,江苏无锡214122

出　　处：《热能动力工程》2016年第11期19-25,共7页Journal of Engineering for Thermal Energy and Power

基　　金：江苏省自然科学基金青年基金项目(BK20130150)

摘　　要：本研究采用三维气动设计方法设计了具有NACA65-810翼型的直叶轮、周向前弯和周向后弯叶轮,并采用计算流体力学软件模拟其气动性能,分析了压力峰值工况和设计工况下3个叶轮叶顶泄漏流和泄漏涡的空间发展和叶顶间隙部分静压损失以及熵分布。结果表明:直叶轮引入周向前弯后,叶顶泄漏流的卷吸能力降低,泄漏涡起源位置向远离叶片前缘的方向迁移,泄漏涡涡心径向高度得到了保持,降低了叶顶泄漏涡与主流的干涉作用;引入周向后弯后,泄漏流的卷吸能力增强,泄漏涡的起源位置向靠近叶片前缘的方向迁移,远离叶片前缘的涡心径向高度显著降低,涡核下游弥散范围扩大,增强了叶顶泄漏流与主流的干涉作用,不利于降低叶顶泄漏损失。A straight impeller equipped with the NACA65-810 airfoil and impellers installed with blades forward and backwards bent respectively along the circumferential direction were designed by using a three-dimensional aerodynamic design method and a CFD( computational fluid dynamics) software was adopted to simulate their aerodynamic performance and analyze the spacial development of their leakage flows and vortexes in the three blade tip clearances beyond the impeller as well as the distribution of the static pressure losses and entropy in the blade tip clearances.It has been found that after the straight impeller had been forward bent along the circumferential direction,the entrainment ability of the leakage flow in the blade tip clearance will become weak and the initial location of the leakage vortexes will shift to a location away from the leading edge of the blades with the height of the center of the leakage vortex along the radial direction being kept unchanged,thus weakening the interference of the blade tip leakage vortex to the main stream. After the straight impeller had been backwards bent along the circumferential direction,the entrainment ability of the leakage flow in the blade tip clearance will become strong and the initial location of the leakage vortexes will shift to a location close to the leading edge of the blades with the height of the center of the leakage vortex along the radial direction away from the leading edge of the blade being notably lowered,thus expanding the dispersion range of the vortex core at the downstream,strengthening the interference of the blade tip leakage vortex with the main stream and unfavorable to lowering the blade tip leakage losses.

关 键 词：NACA65翼型 周向弯曲 叶顶间隙 泄漏流 数值分析 

分 类 号：TH312[机械工程—机械制造及自动化]