The architecture of aeroengine air-cooling system channels is notably intricate, with impingement heat transfer standing out as a critical process amidst the complexity. This study delves into the casing annular cavity’s structure, examining the influence of flow and structural parameters on heat transfer characteristics. Experimental findings have revealed a trend towards more uniform temperature distributions across the impingement target plate as the relative impingement distance (H/d) increases, under a constant impingement Reynolds number (Re_j). Notably, an impingement angle (β) of 90° yields optimal heat transfer effects on the target surface. Furthermore, a higher impingement hole consistency (Is) correlates with a lower and more uniform temperature distribution across the target plate. Additionally, escalating the crossflow ratio (m_c/m) results in a decline in the temperature at the impingement stagnation point and a corresponding rise in the heat transfer coefficient.

With the increasing power output of aero-engines, combustor hot-gas mass flow rate and temperature continue to rise, posing more severe challenges to combustor structural cooling design. To enhance the film-cooling performance of the Z-profile feature in a reverse-flow combustor, this study performs a multi-parameter numerical optimization by integrating computational fluid dynamics (CFD), a radial basis function neural network (RBFNN), and a genetic algorithm (GA). The hole inclination angle, hole pitch, row spacing, and the distance between the first-row holes and the hot-side wall are selected as design variables, and the area-averaged adiabatic film-cooling effectiveness over a critical downstream region is adopted as the optimization objective. The RBFNN surrogate model trained on 750 CFD samples exhibits high predictive accuracy (correlation coefficient (R > 0.999)). The GA converges after approximately 50 generations and identifies an optimal configuration (Opt C). Numerical results indicate that Opt C produces more favorable vortex organization and near-wall flow characteristics, thereby achieving superior cooling performance in the target region; its average adiabatic film-cooling effectiveness is improved by 7.01% and 9.64% relative to the reference configurations Ref D and Ref E, respectively.