Numerical Investigations of Film Cooling Characteristics of Interrupted Slot and Trench Holes on a Vane Endwall  

作　　者：XIAO Xiangtao WANG Pei DU Qiang XU Qingzong LIU Jun ZHU Junqiang 

机构地区：[1]Key Lab of Light-duty Gas-turbine,Institute of Engineering Thermophysics,Chinese Academy of Sciences,Beijing 100190,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]Innovation Academy for Light-duty Gas Turbine,Chinese Academy of Sciences,Beijing 100190,China

出　　处：《Journal of Thermal Science》2021年第3期1010-1024,共15页热科学学报（英文版）

基　　金：financial support of National Natural Science Foundation of China(Grant No.51776200);National Science and Technology Major Project(2017-Ⅲ-0003-0027);Youth Innovation Promotion Association of the Chinese Academy of Sciences。

摘　　要：This paper describes film cooling characteristics of the novel combined configuration employing interrupted slot and trench holes on a vane endwall.Interrupted slot,formed by uneven thermal expansion between combustor and high-pressure turbine vane,can improve adiabatic film cooling effectiveness of the leading edge and pressure side-endwall junction by inhibiting the development of horseshoes vortex.Holes embedded into a straight trench were introduced to improve film efficiency comparing to cylindrical holes on vane passage endwall.The influences of lateral pressure gradient,slot coolant and step on crossflow of the hole coolant in trench were mainly discussed.Three dimensional Reynolds-averaged Navier-Stokes equations with shear stress turbulence model(SST k-ω)were used to obtain the flowfields and adiabatic film cooling effectiveness of a cascade model.Four hole blowing ratios M=0.5,1.0,1.5,2.0 and two axial positions X/Cax=–0.05,0 were considered.The coolant crossflow in trench on flat endwall of cascade passage trends to flow towards suction side due to the lateral pressure gradient rather than both sides on flat plate.For combined configuration of interrupted slot and trench holes,the step vortex rolls up hole coolant upstream of trench which changesηdistributions comparing to that on flat passage endwall.Comparing to the cylindrical holes,better film cooling performance can still be obtained when arranging trench holes under high blowing ratios.The influence of hole’s axial positions was also discussed.

关 键 词：film cooling trench holes blowing ratio lateral pressure gradient step vortex axial position 

分 类 号：TK474.811[动力工程及工程热物理—动力机械及工程]