Numerical investigation of the initiation and propagation of oblique detonation waves in a confined combustion chamber

Different from the phenomena in a semi-infinite domain, the initiation and propagation of oblique detonation wave in a confined combustion chamber are more complicated. Two detonation initiation modes are identified in the supersonic flow, strong initiation whose detonation wave is directly triggered after the first shock wave or reflected shock waves, and mild initiation which is characterized by self-initiation at a long distance after the first shock wave or reflected shock waves in the low Mach number flows. The standing oblique detonation wave could be initiated either by the induced shock, as long as the induced shock is strong enough, or by the subsequent reflections from the wall of the combustion chamber as well. When the velocity of supersonic incoming flow is as low as Chapman-Jouguet velocity, a pulsed-oscillating detonation wave has been maintained in the chamber with the means of changing the equivalence ratio between 0.7 and 1.0 at Ma = 3.15.