Continuous rotating detonation engine fueled by ammonia

Abstract

As a carbon-free fuel, ammonia has attracted increasing interests while the corresponding utilizations are still limited. In this paper, ammonia-oxygen continuous rotating detonation (CRD) was firstly proposed and realized in the hollow chamber with Laval nozzle. The formation process and propagation characteristics were investigated through pressure measurement and optical observation. The CRD wave formation time increased with the nozzle contraction ratio, which was mainly attributed to the slower injection recovery process under the higher chamber pressure. The operation range was large, and the CRD wave propagated in single-wave mode with the velocity of 1806 m/s in the chosen test. The propagation velocity did not increase continuously as the equivalence ratio increased, which could be attributed to the changeable reaction mechanisms and the slow heat release of ammonia. The coupling of ammonia injection and CRD wave propagation was analyzed under both supersonic and subsonic injection conditions. The synchronous fluctuations of the pressure in ammonia plenum and the intensity of detonation waves proved that the coupling was very tight under subsonic injection condition. This paper was beneficial to the improvement of the detonation theory, and it provided an efficient approach to the utilization of ammonia.