Heat Transfer and Aerodynamics of Complex Shroud Leakage Flows in a Low-Pressure Turbine  

作　　者：Wang Pei Du Qiang Yang Xiao Jie Zhu Jun Qiang 

机构地区：[1]Institute of Engineering Thermophysics Chinese Academy of Sciences [2]University of Chinese Academy of Sciences

出　　处：《Journal of Thermal Science》2013年第5期447-458,共12页热科学学报（英文版）

基　　金：supported by grants from the National Natural Science Foundation of China(No.51306177)

摘　　要：A numerical investigation on over-shroud & inter-shroud leakage flow has been carried out to explore the underneath flow physics at the stage of shrouded Low Pressure(LP) turbine.Compared with the No inter-Shroud gap's Leakage flow Model(NSLM) and With inter-Shroud gap's Leakage flow Model(WSLM),the aerodynamic characteristics and the heat transfer performance have been studied.Through the aerodynamic point of view,it is concluded that due to the pressure difference between the rotor's passage and the over-shroud cavity,in the stream-wise direction,flow structure has been modified,and the inter-shroud leakage flow may even cause flow separation in the vicinity of the blade passage's throat.In the circumferential direction,separation flows appear over the rotor's shroud surface(upper platform of the shroud).Meanwhile,from the point of view of heat transfer,further provision on contour maps of the non-dimensional Nusselt number reveals that the reattachment of leakage flow would enhance the heat transfer rates and endanger the rotor's labyrinth fins over the shroud.However,due to the limited amount of inter-shroud leakage flow(current computational model),temperature distribution variation along the blade surface(near the rotor's tip section) seems to have only minor insignificant differences.At the end of the paper,the author puts forward some recommendations for the purpose of future successful turbine design.

关 键 词：over-shroud leakage flow inter-shroud leakage flow shrouded LP turbine 

分 类 号：TK14[动力工程及工程热物理—热能工程]