间隙高度对涡轮叶顶间隙流动的影响  

EFFECT OF TIP CLEARANCE HEIGHT ON TIP CLEARANCE FLOW IN-TURBINE ROTORS

作　　者：牛茂升[1] 臧述升[1] 黄名海[1] 

机构地区：[1]上海交通大学机械与动力工程学院叶轮机械研究所,上海200240

出　　处：《工程热物理学报》2008年第6期935-939,共5页Journal of Engineering Thermophysics

摘　　要：叶顶间隙流动是导致涡轮动叶中产生流动损失的主要原因之一。对某动力涡轮第一级内三维流动的数值计算结果表明,流体在经过动叶叶顶间隙以后在约25%叶顶轴向弦长处(τ=3 mm)在叶顶与吸力边夹角处卷起形成间隙涡,造成流动阻塞,同时在间隙内叶片顶部10%叶顶轴向弦长处(τ=3 mm)开始在压力边出现叶顶分离涡,使得间隙流动损失增加。随着间隙高度增大,通过间隙的流量增加,间隙涡形成位置后移,间隙涡、叶顶分离涡尺寸变大,在流道内影响范围增大,导致流动损失变大。Tip clearance flow is one of the most important resources of losses in turbine rotors. From a computation of the three dimensional flow in the first stage in a power turbine, it can be indicated that when tip clearance height is 3 mm, the fluid roll up to form tip clearance vortex at the corner between blade tip and suction surface at about 25% axial chord, resulting in the blockage of main flow. And on the blade tip near pressure surface, tip separation vortex shows up at 10% axial chord, and losses induced by tip clearance flow increase. As tip clearance height increases, the mass flow that come through the tiny gap increases, the inception of tip clearance vortex moves downstream, the size of both tip clearance vortex and tip separation vortex, their influence area and total losses increase.

关 键 词：涡轮动叶 叶顶间隙流动 间隙涡 叶顶分离涡 

分 类 号：TK474.7[动力工程及工程热物理—动力机械及工程]