Film cooling performance analysis of different multi-row cooling hole configurations.

Abstract

This paper investigates film cooling flow over a flat plate with five different cooling hole configurations. These configurations include a combined arrangement of cylindrical and fan-shaped holes. Numerical simulations are performed using the open-source computational fluid dynamics (CFD) platform OpenFOAM. The study is performed at two different mainstream Mach numbers ([Formula: see text] and [Formula: see text]) and three different blowing ratios ([Formula: see text], [Formula: see text], and [Formula: see text]), while maintaining a coolant density ratio of approximately [Formula: see text]. To enable accurate and physically consistent boundary conditions, a mathematical equation is presented to compute the total pressure of the coolant at the inlet as a function of blowing ratio, density ratio, and mainstream Mach number. Across all conditions, staggered fan-shaped configurations exhibited the highest cooling effectiveness. At the higher Mach number ([Formula: see text]) and higher blowing ratio ([Formula: see text]), an asymmetric coolant distribution was observed for the fan-shaped hole geometries. This asymmetry was attributed to flow separation within the fan-shaped coolant channel. This asymmetric coolant distribution leads to a significant drop in cooling performance, resulting in an approximate 60% reduction in the averaged film cooling effectiveness for staggered fan-shaped compared with [Formula: see text] at the same blowing ratio.