Numerical Investigation of Gas Turbine Combustor Cooling Performance with Bézier Effusion Holes

A novel gas turbine combustor effusion hole concept was simulated under realistic fuel-lean operating conditions in the present work. Simulations were conducted in ANSYS Fluent, using a steady-state Reynolds-averaged Navier–Stokes conjugate heat transfer model along with the [Formula: see text] shear-stress transport turbulence model. The hole’s bore was defined using a quadratic Bézier curve, enabling efficient cooling air injection over the liner. With applications in combustor liner cooling, a staggered array of holes was modeled with 16 rows in the streamwise direction over a 0.15 m length. Modifications to the hole’s inlet and spanwise expansion were made to observe their effect on cooling performance in terms of combustor liner temperatures, wall heat flux, and trends in film-cooling effectiveness. Results show that the addition of a rounded inlet increased velocity in the hole and improved flow attachment but had marginal impact on liner temperature. A higher width expansion yielded greater cooling effectiveness and a more uniform surface heat flux distribution. A narrower effusion hole generally increased streamwise jet momentum and resulted in liftoff and localized hot spots due to the formation of counter-rotating vortices. Complex effusion holes, such as those presented here, will be facilitated by advances in additive manufacturing and serve to improve the thermal efficiency of gas turbines.