Film Cooling in Supersonic Flow: Experiment Design and CFD Investigatio

Researchers worldwide are thriving to increase the efficiency of gas turbine engines. One possible step increase in overall efficiency could be achieved with the implementation of Rotating Detonation Combustors. However, the development of this technology is held back by several technological challenges. One of the most relevant is presented by the management of the extreme thermal load generated by its unique combustion process. In this context, efficient cooling solutions are crucial. Convection cooling showed applicability limits indicating the necessity of a film cooling approach. A literature review has indicated a lack of experimental results investigating the performance of film cooling strategies in supersonic flow, which extensively characterizes the flow field typical of an RDC. This paper describes the procedure followed for the development of a supersonic wind tunnel capable of investigating the film cooling behaviour in a variable Mach Number flow. Adiabatic effectiveness measurements are planned with the use of Binary PSP, which can account for the temperature gradients appearing on the test article. Global fluid dynamics behavior is then investigated with the implementation of a schlieren imaging set up, capable of capturing the morphology of the mixing mechanisms and shock wave generation at the film cooling hole. Low-order CFD investigations are used to predict the flow behaviour allowing the design of the diagnostic facilities according to the required sensitivity. The outcome of the experimental campaign will provide valuable insight into the physics of these phenomena, promoting the development of a high efficiency cooling solution for the RDC.