Numerical simulation of deflagration to detonation transition in granular HMX explosives under thermal ignition

To study the deflagration to detonation transition process in granular explosive under thermal ignition condition, the conductive burning is introduced into the classical model. The novel space-time conservation element and solution element method is applied to solve the mathematical governing equations. The transition process in granular HMX bed which is packed to 85 % of theoretical maximum density is simulated. The development of conductive burning, convective burning and detonation is analyzed. In the early stage, the combustion propagates slowly. It moves no more than 0.2 mm within 8.16 ms. After onset of convective burning, it takes only 20 mu s to form a steady detonation with the velocity of 8165 m s(-1). The time to detonation increases with the decrease in particle diameter.