Effects of Tip Clearance on Blade Loading in a Planar Cascade of Turbine Blades
Effects of Tip Clearance on Blade Loading in a Planar Cascade of Turbine Blades
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DOI：
10.1115/86-gt-245
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发表时间：
1986-06
期刊：
影响因子：
--
通讯作者：
S. Sjolander;K. Amrud
中科院分区：
文献类型：
--
作者：
S. Sjolander;K. Amrud
本文详细研究了大型平面叶栅涡轮叶片中叶尖泄漏流的结构及其对叶片载荷的影响。叶尖间隙为叶片弦的 0.0% 至 2.86%。其中一个叶片配备了 14 排，每排 73 个静态水龙头，可以获取尖端附近负载的非常详细的图片。除了测量之外，还使用烟雾和表面油流进行了广泛的流动可视化。本实验中发现的一个新特征是，随着间隙的增加，形成多个离散的尖端泄漏涡流。从表面油流中可以清楚地看出它们的存在，并且它们解释了叶片压力分布中发现的多个吸力峰值。压力分布的积分表明，对于较大的间隙值，叶片负载随着接近尖端而增加，并且仅在非常接近尖端时才开始下降。发现这种增加主要发生在力的轴向分量中。版权所有 © 1986 by ASME
The paper examines in detail the structure of the tip leakage flow and its effect on the blade loading in a large-scale planar cascade of turbine blades. The tip clearance was varied from 0.0 to 2.86% of the blade chord. One of the blades is instrumented with 14 rows of 73 static taps which allowed a very detailed picture of the loading near the tip to be obtained. In addition to the measurements, extensive flow visualization was conducted using both smoke and surface oil flow. A new feature found in the present experiment was the formation of multiple, discrete tip-leakage vortices as the clearance was increased. Their presence is clearly evident from the surface oil flow and they account for the multiple suction peaks found in the blade pressure distributions. Integration of the pressure distributions showed that for larger values of the clearance the blade loading increases as the tip is approached and only begins to decline very near the tip. The increase was found to occur primarily in the axial component of the force.Copyright © 1986 by ASME