Numerical Investigation on Detonation Control Using a Pulse Hot Jet in Supersonic Combustible Mixture

Abstract

Abstract:To investigate the mechanism of detonation control using a pulse hot jet in the supersonic hydrogen-oxygen mixture, high-resolution simulations with a detailed reaction model were conducted using an adaptive mesh refinement method. After the successful detonation initiation, a contractive passway was generated between the hot jet and the main flow field behind the detonation front. Due to the contractive passway, the expansion of detonation products was prevented, hence resulting in overdriven detonation. By setting up various contractive passways through adjusting the width of the hot jet, the overdrive degree of overdriven detonation also changes. It is suggested that the width of the hot jet has approximately linear relation with the relative and absolute propagation velocities. When the contractive passway gradually disappeared after the shutdown of the hot jet, overdriven detonation attenuated to the dynamically stable Chapman-Jouguet (CJ) detonation. When the contractive passway was re-established once again after the re-injection of the hot jet, the CJ detonation developed to the same overdriven detonation, indicating that the contractive passway controlled by the pulse hot jet can indeed control detonation propagation in the A c c e p t e d M a n u s c r i p t 2 supersonic combustible mixture to some extent.

Detonation interaction with cavity in supersonic combustible mixture

“…As a result, as shown in Fig. 2c, detonation attenuation results in a reduction of numbers of both transverse waves and triple points [43]. Compared with that in Fig.…”

“…It should be noted that if no cavity is embedded in the channel, the attenuated detonation will finally fail and disappear in the channel [43]. Based on this comparison, it is suggested that the cavity-based setup plays an important role in the relatively dynamical sustainment propagation of detonation in supersonic combustible mixtures.…”

“…2a, immediately after the shutdown of the hot jet, an expansion wave is observed. At this moment, five triple points are generated; however, for a CJ detonation under the given condition, normally only two triple points are formed in the channel [43], indicating the formation of an overdriven detonation here. Because of the intrinsic inertia, the detonation continues to propagate forward for a while until it reaches the farthest propagation location approximately at X 7.3 cm, as shown in Fig.…”

“…It is reported that contractive passway can prevent the expansion of detonation products effectively, thus resulting in forward propagation of detonation and eventually formation of overdriven detonation [43]. After the collision of the two triple points in Fig.…”

“…Because of the contractive passway mechanism induced by hot jet [43], overdriven detonation is generated after initiation as it propagates forward toward the supersonic combustible mixture with the CJ velocity. After the shutdown of the hot jet, detonation cannot remain the same overdriven state but gradually attenuates, as shown in Fig.…”