Effects of shock waves interaction on hydrocarbon fueled supersonic film cooling with combustion

Abstract

Abstract In this paper, interaction between oblique shock waves and hydrocarbon fueled supersonic film cooling with combustion is numerically studied using Reynolds-averaged Navier–Stokes equations. Theoretically, the intensity of the reflected shock wave is weaker than the incident shock wave, since the flow deflection angles are the same, whereas the reflected shock sees a smaller upstream Mach number. However, with the film coolant combustion taken into consideration, the shock wave reflects on the flame and the flame is formed apart from the wall, resulting that the flow deflection angle increases. Therefore, the intensities of the reflected shock waves increase. It is found that, as a shock wave interacts on the flame surface, it is also refracted inside the flame besides reflection which induces small-momentum region on the wall. It is worth mentioning that, when the incident shock impingement position locates before the self-ignition point of the cooling film without oblique shock waves interaction, the self-ignition point moves upstream to the shock impingement position, due to the energy accumulation in the shock wave interaction region. And the small-momentum region caused by the incident oblique shock wave interaction is expanded by the film coolant combustion which also increases the reflected shock wave intensity. Moreover, the shock wave interaction reduces the cooling performance beneficial effect region and increases the skin friction reduction region brought by the combustion. Otherwise, oblique shock waves interaction has no effects on the self-ignition point position and the skin friction reduction region. The incident shock impingement position moving downstream far away from the self-ignition point could be helpful to achieve a better cooling performance.