Influence of Gas-to-Wall Temperature Ratio on the Leakage Flow and Cooling Performance of a Turbine Squealer Tip

In high-pressure turbines, there is a large difference in temperature between the mainstream and turbine blade surface. Most of tip heat transfer studies were conducted under assumption that Over-Tip-Leakage (OTL) flow field independent wall thermal condition. Recent numerical experimental have revealed two-way coupling effect aerodynamics should not be neglected. The coefficient obtained by conventional method able to match realistic engine condition accurately. This study investigates impact boundary on cooling performance squealer blades. RANS CFD result was validated against data from high-speed test rig with relative casing motion. aerothermal for both uncooled cooled tips studied at two different gas-to-wall ratios, 1.7 1.1; reference 204 K. It found location strength cavity vortices varied conditions, leading signatures performance. recommended film effectiveness near-adiabatic corrected before their application design process. would more reliable wall-to-gas ratio during study.