可调导叶端壁间隙泄漏损失控制方法研究

Investigation on the Control Strategy of Variable Guide Vane Endwall Gap Leakage Loss

为了减小可调导叶端壁间隙引起泄露损失,在导叶两端分别增加一个圆盘,圆盘分别嵌入到机匣和轮毂内,导叶附近的机匣和轮毂设计为同心球面,圆盘在流道内的表面分别与机匣和轮毂共球面,同时导叶的旋转轴过球心,保证了导叶旋转时流道保持一致。通过数值模拟的方法对比分析了导叶两端增加圆盘设计与导叶两端无间隙和全间隙时涡轮的性能,结果表明:导叶两端增加圆盘设计可明显减小可调导叶端壁间隙引起的泄露损失,提高涡轮的性能。

In order to reduce the leakage loss of the variable guide（VGT） vanes endwall, a disk at each end of the VGT was added, and they were embedded in hub and casing, respectively. The shapes of hub and casing around the VGT were designed to be concentric spheres, and the surface of the disk on the flow passage side were also at same sphere of hub and casing, respectively. The rotation axis of VGT passed through the center of sphere to keep flow path unchanged when VGT rotated. The paper numerically investigated the turbine performance when VGT ends having two disks in terms of the endwalls with and without gaps. The result indicated that adding a disk on the VGT both end could reduce the leakage loss and improve turbine performance.