Numerical investigation of gas turbine combustor cooling performance with Bézier effusion holes

Kurzfassung

A novel gas turbine combustor effusion hole concept was simulated under realistic fuel-lean operating conditions in the present work. The hole's bore was defined using a quadratic Bézier curve, enabling efficient cooling air injection over the liner. Modifications to the hole's inlet and width expansion were made to observe their effect on cooling performance. Results show that the addition of an inlet fillet 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 injection hole generally increased streamwise jet momentum and resulted in lift-off and localized hot spots due to 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.