Continuous Detonation of a Hydrogen-air Mixture in the Air Ejection Mode

The present paper summarizes the results of the continuous detonation investigations in the oxidizer ejection mode performed at the Lavrentyev Institute of Hydrodynamics. The objective of these investigations was to obtain continuous detonation combustion at flight Mach number M = 0 and to determine the domain of existence of continuous detonation of a hydrogen-air mixture in the air ejection mode in a flow-type annular combustor in terms of the specific flow rate of hydrogen, the width of the air ejection slot, and the size of the fuel injector orifices, and also to perform tests with long time operation of the combustor. Stable regimes of continuous detonation with one and two transverse detonation waves having velocities 1.48 - 1.16 km/sec are observed in experiments. The size of the slot for air ejection, providing a necessary flow rate for detonation and necessary ratio of the species in the mixture, is determined. The existence of an optimal injector-orifice geometry, which increases the domain of existence of detonation regimes, was elucidated. It was proved by experiments that the combustor used can operate up to 6 s without cooling. Obtaining continuous detonation in the regime of air injection (with M = 0) means that it can exist at least in the entire subsonic range of flight Mach numbers.