The dynamics of detonation evolution in a condensed-phase explosive, initiated by the shock-induced collapse of an embedded, ellipsoidal, gas-filled cavity, is examined computationally. Attention is focused on the details of the evolutionary process following the collapse. The reaction rate is assumed to be pressure-dependent, switching on when the pressure exceeds an ignition threshold. The st...

In this paper we give error estimates on the random projection methods, recently introduced by the authors, for numerical simulations of the hyperbolic conservation laws with stiff reaction terms: ut + f (u)x =− ε (u− α)(u2 − 1), −1 < α < 1. In this problem, the reaction time ε is small, making the problem numerically stiff. A classic spurious numerical phenomenon—the incorrect shock speed—occu...

A study was performed to elucidate the chemical-kinetic mechanism of combustion of toluene. A detailed chemical-kinetic mechanism for toluene was improved by adding a more accurate description of the phenyl + O2 reaction channels, toluene decomposition reactions and the benzyl + O reaction. Results of the chemical kinetic mechanism are compared with experimental data obtained from premixed and ...

extended abstract: introduction the complexity of the phenomenon of time and its meaning has always been considered an obstacle to understanding the nature of time. time is an important phenomenon in detailed discussions about its nature, particularly in philosophy and physics filed. sun, earth and rotations it should be considered a major factor in the definition of the concept of astronomical...

abstract in the recent decades, the iranian economy has been highly depended on oil revenues. considering the fact that a great part of non-oil exports are agricultures product, studying factors influencing growth of agricultural sector plays an important role in the iran's economy. supply domestic shocks and domestic demand pressure along with deviation of exchange rates from its equilibrium, ...

Particle acceleration at astrophysical shocks may be very efficient if magnetic scattering is self-generated by the same particles. This nonlinear process adds to the nonlinear modification of the shock due to the dynamical reaction of the accelerated particles on the shock. Building on a previous general solution of the problem of particle acceleration with arbitrary diffusion coefficients (Am...

We report herein first principles simulations of water under shock loading and the chemical reactivity under these hot, compressed conditions. Using a recently developed simulation technique for shock compression, we observe that water achieves chemical equilibrium in less than 2 ps for all shock conditions studied. We make comparison to the experimental results for the Hugoniot pressure and de...