AUTHOR=Kong Zhiqi , Zhang Tianyi , Du Wei 

TITLE=Influence of grooved rib tip structure on tip loss and heat transfer in a gas turbine blade

JOURNAL=Frontiers in Energy Research

VOLUME=Volume 10 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/energy-research/articles/10.3389/fenrg.2022.994811

DOI=10.3389/fenrg.2022.994811

ISSN=2296-598X

ABSTRACT=This study focuses on the effects of three groove tip structures (full rib groove tip, partial rib tip on suction side, and partial rib tip on pressure side) on tip leakage flow, aerodynamic characteristics of cascade, and heat transfer in a gas turbine blade. The groove width B=1.6mm while the tip clearance τ=1.2mm. Results of the flow parameters, fluid flow and heat transfer in the recessed channel are discussed. The results show that all ribbed tips obtain more uniform outlet flow angle distribution and higher aerodynamic performance than the plane tips. The total aerodynamic pressure loss of the ribbed tips on the pressure side is the same as those of complete ribbed tips. The evolution mechanisms are different, although both can improve turbine efficiency. Although the partial rib tip on the pressure side weakens the mixing of channel vortex and leakage vortex near the trailing edge and has the best control effect on the leakage vortex, the lack of suction side rib will make it easier for low-energy fluid to flow into the gap from the front of the suction side, which is not conducive to reducing the leakage flow inside the gap, the full rib tip not only minimizes the tip relative leakage flow and leakage loss but also increases the channel vortex loss. With the complex vortex system in the groove and the rib blocking effect at the leakage outlet, the suction side rib tip becomes the tip structure with the best leakage flow control effect under the same clearance, but the leakage vortex loss is the highest.