Influence of incidence angle and squealer tip cutback on the aerothermal performance of a transonic turbine blade

Experimental and numerical investigations were conducted to examine the influence of inlet incidence angle and squealer tip cutback on a turbine blade. The measurements of aerodynamic loss and tip heat transfer were performed under transonic conditions. Numerical models were established and validated using experimental data to gain insight into the underlying flow and thermal physics. The results demonstrate that as the incidence angle increases, the strength of TLV and UPV is significantly intensified, leading to a substantial increase in aerodynamic losses. Compared to the baseline case, a positive incidence angle of 7.5 degrees can result in a 21.2% rise in the area-averaged TPL, while a negative incidence angle of - 7.5 degrees can reduce the area-averaged TPL by 3.2%. Moreover, the changes in incidence angle have a significant impact on the distribution of heat transfer within the tip cavity. Furthermore, a cutback squealer tip configuration was proposed and compared to a full squealer tip under a positive incidence condition. The results show that by implementing a tip cutback configuration, the leakage loss of the turbine blade can be reduced by 4.1%. Additionally, there were notable changes in tip heat transfer near the notched rim and trailing edge when employing the cutback tip.