Numerical investigation of heat transfer characteristics of Pin-Fins with C-Shaped-Recessed endwall in gas turbine blades internal cooling channel

Pin -fin cooling has long been a crucial technique employed in gas turbine blades to manage the extreme thermal conditions experienced during operation. While numerous studies have investigated the heat transfer characteristics of different pin-fin configurations, the substantial impact of the endwall of the cooling channel on the heat transfer capability of turbine blades has not received adequate attention or thorough investigation. This research paper focuses on studying the influence of a novel geometry, termed C-shaped-recessed endwall, on pin-fin cooling channels in gas turbine blades. The primary objective of this investigation is to analyze the vortex formation and its impact on heat transfer characteristics within the cooling system. The study involved testing five different pin-fin arrays with C-shaped-recessed endwalls inserted between them, spanning a Reynolds number range of 7400 to 36000. The results show that with reference geometrical values, the new geometry increases the Heat Transfer Efficiency Index (HTEI) by 36.53 % compared to the flat endwall at Re = 29000. Higher heat transfer capacities were achieved by manipulating the C-shaped-recessed endwall heights and width of indentations, and the peak HTEI recorded an increase of 49.75 % at Re = 29000 compared to the flat endwall. The findings from this study underscore the potential of the C-shaped-recessed endwall geometry to improve the heat transfer capability of pin -fins by optimizing endwall configurations.