Tip Clearance Flows in Turbine Cascades
This article describes the effects of some factors on the tip clearance flow in axial linear turbine cascades.The measurements of the total pressure loss coefficient are made at the cascade outlets by using a five-hole probe at exit Mach numbers of 0.10,0.14 and 0.19.At each exit Mach number,experiments axe performed at the tip clearance heights of 1.0%,1.5%,2.0%,2.5% and 3.0% of the blade height.The effects of the non-uniform tip clearance height of each blade in the pitchwise direction are also studied.The results show that at a given tip clearance height,generally,total pressure loss rises with exit Mach numbers proportionally.At a fixed exit Mach number,the total pressure loss augments nearly proportionally as the tip clearance height increases.The increased tip clearance heights in the tip regions of two adjacent blades are to be blame for the larger clearance loss of the center blade.Compared to the effects of the tip clearance height,the effects of the exit Mach number and the pitchwise variation of the tip clearance height on the cascade total pressure loss are so less significant to be omitted.
作 者： Li Wei Qiao Weiyang Sun Dawei 作者单位： College of Propulsion and Energy,Northwestern Polytechnical University,Xi'an 710072,China 刊 名： 中国航空学报（英文版） ISTIC 英文刊名： CHINESE JOURNAL OF AERONAUTICS 年，卷(期)： 2008 21(3) 分类号： V2 关键词： tip clearance flow turbine cascade tip clearance height total pressure loss coefficient