Initiation of Detonation in a Large Tube

摘要

One of the important design criteria in the development of Pulse Detonation Engines (PDEs) is to stabilize detonation in a large-diameter tube in the shortest possible distance. The initial shock train emanating from the ignition source plays an important role in transitioning the deflagration wave into a detonation. To sustain such transition in a large diameter tube. innovative methods and strategies are required. An experimental-numerical investigation is conducted to understand the role of a contoured body suspended within the tube for enhancing detonation transition. A computational fluid dynamics (CFD) code based on flux corrected transport is used for the simuation of the fate of the twvo-dimensional detonation wave formed from the ignition source and expanded through the gap benveen the centerbody and the channel walls. It is found that the reflection of transverse waves at the walls and their collision near the leading shock front are critical in sustaining a detonation wave during expansion. The shock-wall and shock-shock interactions are enhanced by the centerbody. Simuations further suggested that the effectiveness of the inserted centerbody strongly depends on its length.