Effects of inflow parameters on thermal protection and drag reduction characteristics for hydrocarbon fueled supersonic film with combustion

Abstract

Hydrocarbon fueled supersonic film is considered to be one of the most effective methods for achieving thermal protection and drag reduction meanwhile in scramjet combustors. In this paper, the effects of film and mainstream inflow parameters on thermal protection and drag reduction characteristics for hydrocarbon fueled supersonic film with combustion are numerically investigated. The results indicate that, based on the traditional supersonic film without chemical reaction, combustion brings beneficial effects on thermal protection and drag reduction characteristics mainly depend on the relative proportion and location of exothermic chemical reactions in the boundary layer. It is found that, film inflow parameters only change the reaction energy spatial distribution through changing mainstream energy addition by mixing. However, mainstream inflow parameters directly change reaction conditions, therefore influencing the reaction path, and bringing greater effects on the characteristics. It is worth mentioning that, with film inlet height increases under a constant film equivalence ratio, combustion brings more benefits for both thermal protection and drag reduction characteristics based on the traditional film. Moreover, mainstream Mach number increasing or total temperature decreasing can even inhibit the exothermic reactions, which only brings beneficial effects on thermal protection characteristics, however, barely has effects on drag reduction characteristics.

Keywords

• Scramjet
• Hydrocarbon fuel
• Inflow parameters
• Thermal protection
• Drag reduction