An experimental method for squealer tip flow field considering relative casing motion  

作　　者：Fei ZENG Jinlin DU Lin HUANG Liming XUAN Qiang ZHAO Zhengping ZOU 

机构地区：[1]National Key Laboratory of Science and Technology on Aero-Engine Aero-thermodynamics,School of Energy&Power Engineering,Beihang University,Beijing 100083,China [2]Collaborative Innovation Center for Advanced Aero-Engine,School of Energy&Power Engineering,Beihang University,Beijing 100083,China

出　　处：《Chinese Journal of Aeronautics》2020年第7期1942-1952,共11页中国航空学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.51676005)。

摘　　要：Squealer tip is widely used in turbines to reduce tip leakage loss.In typical turbine environment,the squealer tip leakage flow is affected by multiple factors such as the relative casing motion and the wide range of variable incidence angles.The development of experimental methods which can accurately model the real turbine environment and influencing factors is of great significance to study the squealer tip leakage flow mechanism.In the present paper,a low-speed turbine cascade test facility which can model the relative casing motion and wide range of variable incidence angles(-25°to 55°)is built.Based on the similarity criteria,a high-low speed similarity transformation method of the turbine cascade is established by considering the thickness of the turbine blade.A combined testing method of Particle Image Velocimetry(PIV)and local pressure measurement is proposed to obtain the complex flow structures within the tip cavity.The results show that the experimental method can successfully model the relative casing motion and the wide range of variable incidence angles.The low-speed cascade obtained by the similarity transformation can model the high-speed flow accurately.The measurement technique developed can obtain the complex flow field and successfully capture the scraping vortex within the squealer tip.

关 键 词：Blade tip/casing gap measurement Particle Image Velocimetry(PIV) Relative casing motion Similarity transformation TURBINE Wide range of variable incidence angles 

分 类 号：V231[航空宇航科学与技术—航空宇航推进理论与工程]