RESEARCH ON FILM COOLING CHARACTERISTICS AND MECHANISM OF LONGITUDINAL CORRUGATED HEAT SHIELD IN AFTERBURNER

Taking into consideration both the cooling performance of the afterburner and its effect on suppressing combustion oscillations, the longitudinally corrugated heat shield has found widespread application in the afterburner. This paper employs computational fluid dynamics (CFD) and experimental methods to elucidate the influence mechanisms of key parameters such as momentum ratio, open area, and non-dimensional amplitude on the film cooling effectiveness characteristics of the corrugated plate thermal insulation structure. The results indicate that with an increase in the momentum ratio, the effectiveness of gas film cooling rises, and downstream stabilization occurs with the accumulation of the gas film. However, when the momentum ratio exceeds a certain threshold and continues to increase, excessive local momentum downstream results in a decline in gas film cooling efficiency. Additionally, as the non-dimensional amplitude increases, there is a decrease in gas film cooling efficiency, exacerbated by the increasing oscillations of corrugation. Furthermore, at a constant unit area cold air flow rate, the efficiency of gas film cooling increases with an increase in porosity.