Effects of mid-passage gap with a variable surface angle on a turbine vane endwall’s aerothermal and film cooling performances  

作　　者：Zhiyu LI Kaiyuan ZHANG Zhigang LI Jun LI 

机构地区：[1]Institute of Turbomachinery,Xi’an Jiaotong University,Xi’an 710049,China

出　　处：《Chinese Journal of Aeronautics》2024年第6期20-37,共18页中国航空学报（英文版）

基　　金：supported by the National Science and Technology Major Project,China(No.J2019-II-0011-0031);the National Natural Science Foundation of China(No.51936008).

摘　　要：The mid-passage gap is an inevitable structure in a vane passage due to turbine vanes being manufactured individually.The coolant from this gap is able to prevent hot mainstream ingression and provide cooling protection for the endwall.A novel idea of enlarging the endwall’s coverage area and reducing the endwall’s thermal load by applying the mid-passage gap with variable surface angles is carried out in this paper.The endwall’s aerothermal and film cooling performances under four mid-passage gap modes at three typical mass flow ratio conditions are numerically investigated.Results indicate that under the traditional mid-passage mode,the coolant flows into the mainstream with a perpendicular incidence angle and can’t stick to the endwall.Thus,cooling failure occurs,and the endwall’s thermal load is badly increased.The film cooling level at the suction-side endwall is improved when applying the mid-passage gap of a 45surface angle due to the secondary vortex being suppressed.In addition,when applying the mid-passage gap of a 135surface angle,the horseshoe vortex is pushed away,and the coverage area at the pressure-side endwall is enlarged significantly.The best film cooling performance is achieved when the upstream surface angle is 135and the downstream surface angle is 45due to the adiabatic film cooling effectiveness being increased at both the pressure-and suction-side endwall.When the mass flow ratio is 1.5%,the coverage area is enlarged by 43%,and the area-averaged adiabatic film cooling effectiveness is increased by 37%,when compared with those under the traditional mid-passage mode.

关 键 词：Film cooling Heat transfer Surface angle Mid-passagegap Turbinevane endwall 

分 类 号：V235.1[航空宇航科学与技术—航空宇航推进理论与工程] TK14[动力工程及工程热物理—热能工程]