Aerothermal effects of squealer openings on a cavity tip in a turbine cascade

Abstract Both the aerodynamic and thermal performance are important for a high-pressure turbine design. This paper investigates aerothermal effects of opening on the suction side squealer of a cavity tip in a turbine cascade. There are four cases investigated, ‘Cavity’, ‘Opening 1’, ‘Opening 2’ and ‘Opening 3’. For Opening 1 with an opening area at 15 % axial chord, the opening outflow affects the near-tip flow mainly by interacting with the passage vortex, and the near tip loss increases by less than 3 %. For Opening 2 with an opening area at 12 % axial chord, the near tip loss is lower than Opening 1. By further rounding the edge of the opening area, the loss of the tip with opening is less than 1 % higher than the cavity tip. Nevertheless, the opening tip can achieve a reduction of the thermal load of the suction side squealer inner wall by up to 19 %.