Heat transfer study on a turbine rotor endwall by an improved transient experiment method

Based on a new scheme of transient experiment, the test item has a linear initial temperature distribution between the upper and lower surfaces, so the equipment and operation could be simplified. Studies were done on the flow and heat transfer of a turbine rotor endwall. Results show that the endwall heat transfer is determined by the mainstream Reynolds number, together with the complex secondary flow pattern in the cascade passage. The overall heat transfer rate of the endwall is intensified with the improvement of the mainstream Reynolds number, while the secondary flow induces locally higher heat transfer rate in some regions, including: the region of horseshoe vortex near the leading edge, region where branches of horseshoe vortex pass by, the region downstream near the suction side where passage vortex occurs, and the region where corner vortex occurs. Results show good accordance with current knowledge of the endwall secondary flow.