Composition B is a melt-castable explosive consisting of RDX crystals in a TNT matrix. At elevated temperatures, the TNT can flow or even melt, which affects the particle distribution and therefore the detonation propagation. To study this phenomenon, rate stick experiments were conducted at ambient conditions, at temperatures below the TNT melt, and at temperatures above the TNT melt. We field...

The results of experimental studies during which transition to detonation events occurred are presented. These observations and their interpretation are then discussed, and the conditions for the onset of detonation are described, with particular attention paid to the nature of the phenomena of deflagration-to-detonation transition. The resulting implications for predicting detonation evolution...

An experimental study on pulse detonation engine (PDE) is conducted using hydrogen/air mixtures. Several key issues for PDE development, including valve operation, injection, mixing, filling, cycle repetition, ignition timing, DDT distance and propagation of detonation/quasi-detonation, are investigated. The fuel and oxidizer are injected into PDE from opposite sidewall directions to be well mi...

The WBL model for detonation wave propagation was extended to allow more general initiation in the context of level set methods. Initiation could then be induced fairly seamlessly from reactive flow simulations. The accuracy of WBL detonation compared favourably with results from full reactive flow, and proved surprisingly robust with respect to changes in numerical parameters used to trigger W...

Aims. We present the first full-star three-dimensional explosion simulations of thermonuclear supernovae including parameterized deflagration-to-detonation transitions that occur once the flame enters the distributed burning regime. Methods. Treating the propagation of both the deflagration and the detonation waves in a common front-tracking approach, the detonation is prevented from crossing a...

Peter Diakow Department of Mechanical and Materials Engineering, Queen’s University, Kingston, Canada Synopsis Dimethyl-ether (C2H6O) a common hydrocarbon is increasingly being used as a transportation fuel and as an aerosol propellant, very limited explosion safety data is available for this fuel. Experiments were performed to determine the detonation characteristics of dimethyl-ether air mixt...

The Deflagration to Detonation Transition (DDT) in large arrays (100s) of explosive devices is investigated using large-scale computer simulations running the Uintah Computational Framework. Our particular interest is understanding the fundamental physical mechanisms by which convective deflagration of cylindrical PBX 9501 devices can transition to a fully-developed detonation in transportation...

Detonation velocity is an important parameter for explosive, and it is crucial for many fields such as dynamic chemistry burn models, detonation propagation prediction, explosive performance estimation, and so on. Dual-channel detonation velocity measurement method and system are described. The CFBG sensors are pasted both on the surface and in the center of the explosive cylinder. The length o...

We study a type Ia supernova explosion using three-dimensional numerical simulations based on reactive fluid dynamics. We consider a delayed-detonation model that assumes a deflagration-to-detonation transition. In contrast with the pure deflagration model, the delayed-detonation model releases enough energy to account for a healthy explosion, and does not leave carbon, oxygen, and intermediate...