Conjugate heat transfer analysis of mist-assisted film cooling of a mini-channel embedded flat plate

This article presents a three-dimensional conjugate heat transfer analysis for mist-assisted air film cooling applied to a flat plate. In this computational fluid dynamics (CFD) investigation, a flat plate with 11 film holes served as the baseline configuration. A mini-channel was integrated into the plate wall to investigate the influence of a mini-channel on cooling performance. Steady-state simulations were conducted at a constant blowing ratio M = 0.5, with dry air serving as the coolant and mist concentrations ranging from 2 % to 6 %. The study revealed that mist-assisted film cooling outperforms air film cooling for both the flat plate with only film cooling (FC) and the plate with impingement mini-channel film cooling (IMFC). Notably, both air and mistassisted cooling exhibited similar qualitative trends. For droplet size of 5 mu m, the area-weighted average effectiveness of the IMFC plate showed an improvement of 112 % compared to the FC plate with air cooling. Additionally, it was discovered that cooling performance increased with higher mist concentrations; for 6 % mist concentration (by mass), the area-weighted effectiveness was enhanced by 177 % for the FC plate.