Unsteady wakes-secondary flow interactions in a high-lift low-pressure turbine cascade  

作　　者：Xiao QU Yanfeng ZHANG Xingen LU Junqiang ZHU 

机构地区：[1]Key Laboratory of Light-Duty Gas-Turbine,Institute of Engineering Thermophysics,Chinese Academy of Sciences,Beijing 100190,China [2]School of Engineering Science,University of Chinese Academy of Sciences,Beijing 100190,China

出　　处：《Chinese Journal of Aeronautics》2020年第3期879-892,共14页中国航空学报（英文版）

基　　金：provided by the National Natural Science Foundation of China(Nos.51876202 and 51836008)。

摘　　要：Detailed experimental measurements were conducted to study the interactions between incoming wakes and endwall secondary flow in a high-lift Low-Pressure Turbine(LPT)cascade.All of the measurements were conducted in both the presence and absence of incoming wakes,and numerical analysis was performed to elucidate the flow mechanism.With increasing Reynolds number,the influence of the incoming wakes on suppressing the secondary flow gradually increased owing to the greater influence of incoming wakes on reducing the negative incidence angle at higher Reynolds numbers,leading to a lower blade loading near the leading edge and suppression of the Pressure Side(PS)leg of the horseshoe vortex.However,the effect of unsteady wakes on suppressing the profile losses gradually became weaker owing to the reduced size of the Suction Side(SS)separation bubble and increased mixing loss in the free-flow region at high Reynolds numbers.Incoming wakes clearly improved the aerodynamic performance of the low-pressure turbine cascade at low Reynolds numbers of 25,000 and 50,000.In contrast,at the high Reynolds number of 100,000,the profile loss at the midspan and mass-averaged total losses downstream of the cascade were higher in the presence of wakes than in the absence of wakes,and the unsteady wakes exerted a negative influence on the aerodynamic performance of the LPT cascade.

关 键 词：Experimental study HIGH-LIFT Incoming wakes Low-pressure turbine Secondary flow 

分 类 号：TH69[机械工程—机械制造及自动化]