This work presents an imaging study of the complex and often overlooked early-onset mechanisms deflagration-to-detonation transition (DDT). Columns granular octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) doped with tungsten tracer particles are ignited thermally by hot wire resulting reactions studied via high-speed X-ray radiography utilizing Diamond Light Source synchrotron. The obser...

A radial well has a unique wellbore configuration. Fracture propagation in deflagration fracturing is studied rarely. The mechanism of interaction between fractures, natural and micro-fractures still unknown. Based on continuum mechanics, damage variational principles, numerical model fracture established with the Hamilton principle phase-field theory. effects horizontal principal stress differ...

An approach for the simulation of explosions of ‘‘energetic devices’’ is described. In this context, an energetic device is a metal container filled with a high explosive (HE). Examples include bombs, mines, rocket motors or containers used in storage and transport of HE material. Explosions may occur due to detonation or deflagration of the HE material, with initiation resulting from either me...

We investigate the quantity and composition of unburned material in the outer layers of three normal Type Ia supernovae (SNe Ia): 2000dn, 2002cr and 2004bw. Pristine matter from a white dwarf progenitor is expected to be a mixture of oxygen and carbon in approximately equal abundance. Using near-infrared (NIR, 0.7 − 2.5 µm) spectra, we find that oxygen is abundant while carbon is severely deple...

Dynamics of ethylene autoignition and deflagration-to-detonation transition (DDT) are first numerically investigated in a one-dimensional shock tube using reduced chemistry including 10 species reactions. Different combustion modes through considering various premixed gas equivalence ratios (0.2 [Formula: see text] 2.0) incident wave Mach numbers (1.8[Formula: text]3.2). Four ignition DDT obser...