Numerical analysis of the aerodynamic performance & heat transfer of a transonic turbine with a partial squealer tip

Abstract

The purpose of this study is to evaluate thermal load and aerodynamic performance by applying different shapes of tips depending on the velocity region in a transonic turbine where subsonic and supersonic regions coexist. The RS1S, which is the transonic turbine of SNECMA, is used. To understand the tendencies, geometries A, B and C were created by varying the length of the pressure surface rim and the suction surface rim, and they were compared with a flat tip, squealer tip, pressure surface rim and suction surface rim. BANS computational analysis was performed using the commercial code ANSYS CFX 18.0, and aerodynamic performance was evaluated by using the mass-averaged total pressure loss coefficient at the 133% C-ax and the mass flow rate of tip leakage. Thermal load was also evaluated by using the area-averaged heat transfer coefficient at the tip. Although the mass flow rate of leakage was smallest with the squealer tip, geometry C, the 75% rim of the pressure surface and the suction surface showed the lowest total pressure loss coefficient, which was 6.5% lower than that of the flat tip. In addition, when only the suction surface rim was applied, the area-averaged heat transfer coefficient was 10% lower than that of the flat tip.