Organization of a pulsed mode of combustion in scramjets

A new method is proposed to organize the working process in the combustion chamber of a scramjet. The flow velocity in the combustor is maintained close to the velocity of sound. In a constant-area channel, this situation is achieved by organizing combustion in a pulsed wave structure of the pseudo-shock type whose position is determined by parameters of the external thermal-gas-dynamic pulsed-periodic action on the flow. In the channel part with a variable cross section, the mean Mach number close to unity is maintained by choosing an appropriate degree of combustor expansion and appropriate places of fuel injection. The pulsed mode assists in improvement of fuel-air mixing and in reduction of the combustion zone length. The main advantage of this method is the high efficiency of the process determined by the minimum loss of the total pressure and the maximum increase in temperature. Experimental results are given to confirm the possibility of realization of the pulsed combustion mode.