The inevitable transonic tip leakage flow in unshrouded high pressure gas turbines induces aerodynamic loss and gives rise to heavy thermal loads on the blade tip. In the pursuit of superior gas turbine engine, cavity tips are widely used in high-pressure turbines to reduce the over-tip leakage flow. The present research aims to numerically investigate the influence of the depth of cavity and thickness of squealer rim on the aerothemal performance of the transonic turbine blade. Three-dimensional (3D) Reynolds-Averaged Navier-Stokes (RANS) equations with Spalart-Allmaras turbulence were solved to perform the simulation. The obtained results indicate that the variations of the cavity depth and squealer rim thickness have significant effects on the aerothermal performance of the transonic turbine blade tip regions. The phenomena in this transonic setup are different from the results obtained in subsonic condition. This study quantified that the improvement of aerodynamic efficiency contributed to the enhancement of heat flux on the blade tip in transonic condition by changing the geometry of tip cavity.
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