Numerical and experimental study of supersonic film cooling with cracking hydrocarbon fuel as coolant

This paper proposed the method to extend the cooling capacity of hydrocarbon fuel in a scramjet engine or a combined cycle engine through combining the regenerative cooling with supersonic film cooling, with the gaseous hydrocarbon fuel of the exit of regenerative cooling channel being used as the film coolant. Through basic analysis, the supersonic film cooling with hydrocarbon fuel as coolant was found to be a kind of flow with non-equilibrium cracking reaction, the cracking reaction will have significant effects on the heat transfer characteristics of the cooling film. To validate its feasibility of the supersonic film cooling using gaseous hydrocarbon fuel as coolant and explore its heat and mass transfer characteristics, numerical model and experimental table were established. The numerical and experimental study of supersonic film cooling with cracking n-decane as coolant were carried out. The numerical and experimental results indicate that supersonic film cooling using hydrocarbon fuel as coolant is very efficient, and larger blowing ratio and film thickness were beneficial for improving the film cooling efficiency.