Heat Release Distribution in a Dual-Mode Scramjet Combustor - Measurements and Modeling

To model the performance and operability limits of a dual-mode scramjet engine, the heat release distribution must be accurately predicted. This distribution controls the thermal choking point, and thus the proflles of pressure, Mach number, and heat transfer in the engine. The current research efiort consists of two parts: measurement of heat release distributions from OH* and CH* in a dual-mode combustor, and development of a 1-D scramjet engine performance model. A dual-mode combustor with transverse wall fuel injection and a cavity ∞ameholder is investigated experimentally for air stagnation temperatures of 1270-1520K. The upstream region of the heat release distribution depends on the ∞ame stabilization and spreading. The ∞ame length and downstream region of heat release distribution appear to be mixing limited for all cases. This result is used to develop a combustion model for a quasi-1-D scramjet combustor code.