Reduction of heat transfer and improvement of film cooling effect on squealer tip with multi-rib design concept

A multi-rib design concept was proposed to reduce the heat transfer and enhance film cooling effect on squealer tip. Three different shapes of ribs (i.e. straight ribs, V-shape ribs, and L-shape ribs) were configured in the cavity of squealer tip of a turbine stage. The distributions of heat transfer coefficient (HTC) and film cooling effectiveness (FCE) on the multi-rib squealer tip were numerically predicted and compared against the conventional squealer tip. The results indicate that the configuration of multiple ribs is beneficial to weaken the development of cavity vortex system, and also traps more coolants in the squealer cavity. Compared to the conventional design, the implementation of L-shape ribs reduces the thermal loads on the cavity floor and entire tip by 82.4% and 34.7%, respectively, while the film cooling effects on the cavity floor and the entire tip are enhanced by 21.1 % and 72.2 %, respectively.