In order to study the surface heat transfer of turbine blades with cutback squealer tip

surface heat transfer coefficient was investigated experimentally through a transient wind tunnel experiment for an uncooled blade and a blade with dust purge holes. The experimental outcome was compared with the numerical simulation result. The uncertainty of the experiment was less than 5%. By analyzing the over tip leakage (OTL) flow condition

it revealed that on the uncooled blade tip

due to the cavity vortex and the separation bubbles

high surface heat transfer coefficient values were scattered on squealer rims of both pressure side (PS) and suction side (SS)

and on cavity floor near the leading edge. A strip of low surface heat transfer coefficient values appeared onthe PS of the second half cavity. In the cooled case

coolant flow from dust purge holes was separated into two parts. The high-energy fluid merged into the OTL flow

resulting in multiple high surface heat transfer coefficient distributions on the SS rim

while the low-energy fluid flowed backward along the SS of the cavity. Cooling effectiveness can reach over 0.4 in this region.