Combustion in a Ramjet Combustor with Cavity Flame Holder

Combustion characteristics in a ramjet combustor with cavity flame-holder is studied numerically. Combustor follows a constant area isolator section and comprises of hydrogen fuel injected sonically upstream of the cavity. Secondary fuel injection is performed at the cavity back wall. A diverging section follows the cavity. These concepts are utilized in many designs. Simulations were performed for an entrance Mach number of 1.4. Stagnation temperature is 702 K, corresponding to a flight Mach number of 3.3. Detailed chemical kinetics is taken into account with a reaction mechanism comprising of 9 species and 25 reaction steps. Turbulence is modeled using Menter's shear stress transport model, which is suitable for high speed internal flows. It is observed that flame anchors at the leading edge of the cavity, and the flame is stabilized in the cavity mode rather than the jet-wake mode. Simulation captures all the essential features of the reacting flow field.