Tip cooling injection characteristic of turbine blade based on fluid-solid coupling method

The high-temperature gas leakage flow generated by the turbine tip clearance not only reduces the turbine efficiency, but also exacerbates the thermal load on the tip. Based on experimental model and numerical calculation method of fluid-solid coupling, the flow mechanism of the interaction between gap flow and cooling jet at the tip of turbine groove and the effect of top jet cooling on the heat transfer effect of the groove wall are studied. The effects of the ratio of cooling hole inclination angle, the cooling hole inlet angle, and the thermal conductivity of the solid material on the Nu number of the wall surface are analyzed. The results show that the large blow ratio (M=1.5) can effectively improve the heat transfer between the rib and the bottom of groove near the pressure side, and the Nu number distribution is more uniform. The "jet effect" generated by the intake angle changes the high-speed zone of the cooling airflow. Relative position of the outlet, when the intake angle β>0°, the cooling gas can effectively block the high temperature fluid to reduce the Nu number of the wall surface. The low thermal conductivity material reduces the convective heat transfer of the airflow to the solid wall, so that the convective heat transfer of the wall surface is more uniform. © 2020, Editorial Board of Journal of Harbin Institute of Technology. All right reserved.