Numerical Study of the Aerothermal Behavior and Film-Cooling Efficiency of a Wave Fan-Shaped Hole

Abstract This study investigates the influence of wave fan-shaped holes (WFSHs) on adiabatic film-cooling effectiveness for flat plate configurations. Five configurations were analyzed: a baseline cylindrical hole and four modified geometries, a fan-shaped hole (FSH), and WFSH-1 to WFSH-3. The Reynolds-averaged Navier–Stokes approach with the RNG k–ε turbulence model was used to simulate the 15 cases, corresponding to three blowing ratios (M = 0.5, 1.0, and 1.5). First, to validate the numerical model, satisfactory agreement between the experimental measurements of the baseline case and the computational fluid dynamics results was verified. Next, area-weighted film-cooling efficiencies and discharge coefficients were evaluated, as well as mean efficiency distributions along the centerline and lateral lines. Results indicate that all fan-shaped holes, whether with wave-shaped geometries or not, significantly improve film-cooling performance compared to the baseline, especially at higher blowing ratios exceeding 100% to improve the film-cooling efficiency. However, the tested design of WFSH-2 consistently exhibited superior cooling effectiveness, maintaining better jet attachment and surface coverage. Although these modifications resulted in a moderate decrease in the discharge coefficient, up to 57% compared to the base case.