Effects of Trenched Film Hole Configurations on the Endwall Film Cooling and Suction Side Phantom Cooling  

作　　者：DU Kun LI Zhigang LI Jun 

机构地区：[1]Institute of Turbomachinery, School of Energy & Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China [2]Collaborative Innovation Center of Advanced Aero-Engine, Beijing 100191, China [3]School of Power and Energy, Northwestern Polytechnical University, Xi'an 710072, China

出　　处：《Journal of Thermal Science》2019年第5期905-914,共10页热科学学报（英文版）

基　　金：support of the National Natural Science Foundation (No. 51776151; No.51936008; No. 51776173) of China;supported by “the Fundamental Research Funds for the Central Universities” No. 3102019OQD702

摘　　要：To maximize the turbine thermal efficiency, modern gas turbine’s inlet temperature is significantly augmented within the past few decades. To prolong the lifespan of gas turbines, many efficient cooling techniques have been proposed and applied in the endwall cooling schemes. However, conventional discrete film hole does not take effect at the leading edge nearby region. In this research, how the trenched film hole configurations affects the endwall cooling and phantom cooling characteristics were deeply studied by using a verified approach. Steady 3D Reynolds-averaged Navier-Stokes(RANS) governing equations together with the shear stress transport(SST) k-w turbulence model have been solved. Firstly, results indicate that trenched film holes greatly influence the cooling effectiveness at leading edge nearby region compared to normal case. Nevertheless, suction side phantom cooling is hardly influenced by the trenched film holes. Secondly, the case with a smaller trench width obtains higher endwall cooling effectiveness, particularly at upstream region. More importantly, the cases with W=3D achieve large cooling effectiveness at leading edge nearby region with little influence by trench depth. Additionally, majority of trenched film holes coolant flow is driven towards middle passage. Therefore, the suction side phantom cooling is unaffected by the trenched film holes.To maximize the turbine thermal efficiency, modern gas turbine’s inlet temperature is significantly augmented within the past few decades. To prolong the lifespan of gas turbines, many efficient cooling techniques have been proposed and applied in the endwall cooling schemes. However, conventional discrete film hole does not take effect at the leading edge nearby region. In this research, how the trenched film hole configurations affects the endwall cooling and phantom cooling characteristics were deeply studied by using a verified approach. Steady 3D Reynolds-averaged Navier-Stokes(RANS) governing equations together with the shear stress transport(SST) k-w turbulence model have been solved. Firstly, results indicate that trenched film holes greatly influence the cooling effectiveness at leading edge nearby region compared to normal case. Nevertheless, suction side phantom cooling is hardly influenced by the trenched film holes. Secondly, the case with a smaller trench width obtains higher endwall cooling effectiveness, particularly at upstream region. More importantly, the cases with W=3D achieve large cooling effectiveness at leading edge nearby region with little influence by trench depth. Additionally, majority of trenched film holes coolant flow is driven towards middle passage. Therefore, the suction side phantom cooling is unaffected by the trenched film holes.

关 键 词：gas TURBINE TURBINE ENDWALL COOLING trenched film HOLES PHANTOM COOLING numerical simulations 

分 类 号：O4[理学—物理]