Numerical study of film cooling at the outlet of gas turbine exhaust

Abstract

In order to mitigate the potential operational damage risk caused by traditional cooling methods in engineering applications of heavy-duty gas turbine component testing, the film cooling unit and realizable K-epsilon turbulence model were employed. Numerical simulations were conducted for multiple exhaust film holes with varying curvature and pitch-row under different operating conditions. The heat transfer distribution along the flow direction and radial direction of the high temperature wall was analyzed, as well as the influence of heat transfer under different geometrical parameters. The results indicate that for the integrated configuration of large-diameter cooling units, a blowing ratio of 0.3 yields the most comprehensive cooling effect, primarily due to the extensive spatial coverage by the gas film and the weakening of eddy dissipation mechanisms. Additionally, it was observed that with an increase in hole distance ratio for multiple exhaust film holes, cold air could more stably participate in heat exchange with high-temperature flue gas wake at the outlet of the gas film hole; thus, a hole distance ratio of 3.0 provides optimal comprehensive cooling effects.