Effect of lid height and blowing ratio on film cooling effectiveness of a novel lidded hole configuration

Abstract

Film cooling is one of the promising technologies used for protecting rocket nozzles and turbine blades from combustion chamber hot gases. This paper proposes a novel shape of film cooling injection hole, called lidded hole, that can offer significant enhancement of cooling performance. ANSYS CFX is used to perform 3D numerical simulations of a flat plate with a single row of lidded holes, in which the k–ε model approximates turbulence effects. Four cases are investigated to highlight the influence of the hole's lid height (H/d = 0, 0.25, 0.5, 0.75). The effect of blowing ratios (M = 0.5, 1, 1.5) is also analyzed for each configuration. The numerical results of this study are compared with available experimental data, and, generally, a good agreement is achieved. The results obtained show that the lidded hole configuration reduces the coolant flow separation which improves significantly the film cooling effectiveness. In addition, increasing the blowing ratio leads to an increase in lateral and centerline cooling effectiveness. Comparing all studied cases, the optimum coolant coverage was obtained for the lidded hole configuration with H/d = 0.25 at M = 1.5.

Enhancement of Film Cooling Effectiveness in a Supersonic Nozzle

“… Comparison of simulated temperature distribution along the nozzle wall with experimental data from [ 26 ]. …”

“…The interaction of a liquid-phase film coolant and the core flow was studied numerically for a semi-cryogenic configuration by Strokach et al [ 25 ]. In a recent numerical study, Guealalia et al [ 26 ] explored the benefits of a novel approach to film injection, namely, a ‘lidded hole’ shape. The method was found to have the potential to improve cooling effectiveness significantly.…”

Effects of Crescent Shaped Block Width and Length on Flow Field and Film Cooling Performance

“…Yuen and Martinez-Botas [13,14] provided in their research papers results of heat transfer for a flat plate configuration. In order to enhance film cooling effectiveness, new hole shape of film cooling (lidded hole) was proposed in the work of Guelailia et al [15]. The effects of surface radial and longitudinal curvature on the performance of film cooling was investigated by Guelailia et al [16,17].…”