Heat-Transfer Coefficients of a Turbine Blade-Tip and Near-Tip Regions

The detailed distribution of heat-transfer coefficients on a gas turbine blade tip was measured using a hue-detection-based transient liquid crystals technique. The heat-transfer coefficients on the shroud and near-tip regions of the pressure and suction sides of a blade were also measured. Tests were performed on a five-bladed linear cascade with a blowdown facility. The Reynolds number based on the cascade exit velocity and axial chord length of a blade was 1.1 x 10 6 , and the overall pressure ratio was 1.2. The heat-transfer measurements were made at the three different tip gap clearances of 1.0, 1.5, and 2.5% of blade span