The structure of a two-phase steady detonation in a granulated solid propellant is studied, and existence conditions for a one-dimensional, steady two-phase detonation are given. Ordinary differential equations from continuum mixture theory are solved numerically to determine steady wave structure. In the limiting case where heat transfer and compaction effects are negligible, the model reduces...

Combining ab initio quantum mechanics with a dipole-field model to describe acid dissociation reactions in water: First-principles free energy and entropy calculations Modeling deflagration-to-detonation transition in granular explosive pentaerythritol tetranitrate Simulated thermal decomposition and detonation of nitrogen cubane by molecular dynamics

This paper describes oneand two-dimensional numerical simulations, with simplified as well as full reaction kinetics, of a single cycle pulse detonation engine (PDE). Focus of the present studies is on 1) the presence of a nozzle extension at the end of the tube, and its effect on performance parameters as well as noise characteristics, 2) critical “spark ignition” energies associated with the ...

Despite many computer based codes like CHEETAH, TIGER, RUBY, BKW, etc. the velocity of detonation (VOD) for explosive molecules and explosive mixtures (formulations) is estimated by several empirical formulations. This article discusses various approaches for the estimation of the velocity of detonation by empirical mathematical equations. The formulation proposed by Kamlet in 1968 is the oldes...

We study a projection and upwind finite difference scheme for a combustion model problem. Convergence to weak solutions is proved under the Courant-Friedrichs-Lewy condition. More assumptions are given on the ignition temperature; then convergence to strong detonation wave solutions or to weak detonation wave solutions is proved.

Size is a defining characteristic of nanoparticles; it influences their optical and electronic properties as well as their interactions with molecules and macromolecules. Producing nanoparticles with narrow size distributions remains one of the main challenges to their utilization. At this time, the number of practical approaches to optimize the size distribution of nanoparticles in many intere...

Radionuclide signals from underground nuclear explosions (UNEs) are strongly influenced by the surrounding hydrogeologic regime. One effect of containment is delay of detonation-produced radioxenon reaching the surface as well as lengthening of its period of detectability compared to uncontained explosions. Using a field-scale tracer experiment, we evaluate important transport properties of a f...

The propagation of a detonation wave remains one of the challenging problems in physics. While it is possible to predict the average propagation velocity almost correctly using classical theory [1, 2], there is no theory to explain the internal flow structure satisfactorily. The famous Zel’dovich-von Neumann-Döring theory [3, 4, 5] is widely considered to describe the one-dimensional detonation...

We study a Type Ia supernova explosion using large-scale three-dimensional numerical simulations based on reactive fluid dynamics with a simplified mechanism for nuclear reactions and energy release. The initial deflagration stage of the explosion involves a subsonic turbulent thermonuclear flame propagating in the gravitational field of an expanding white dwarf. The deflagration produces an in...

Explosion metal welding is high-speed angle oblique collision of two or more metal plates caused by detonation. The metal is joined – welded under high dynamic pressure creating by plastic deformation the waves on the bond interface, accompanied by local adiabatic heating 1 . The explosive metal cladding process can be divided into three stages: a) generation of explosion energy through the det...