The oblique detonation, a combustion process initiated by an oblique shock, arises in most supersonic combustion applications including, most notably, the ram accelerator and the oblique detonation wave engine. Additionally, it is the generic two-dimensional compressible shocked reacting flow; consequently, its basic research value is inherent. The outstanding theoretical questions are also the...

The detonation processes occurring in a variable cross section detonation chamber are compared with that occurring in a simple, constant cross section tube. The variable cross section chamber is made up of a large tube and two small identical tubes connected on each side through frustums. The simple tube has the same diameter as the small tubes of the variable cross section chamber and the same...

Here we analyze properties of an equation that we previously proposed to model the dynamics of unstable detonation waves [A. R. Kasimov, L. M. Faria, and R. R. Rosales, Model for shock wave chaos, Phys. Rev. Lett., 110 (2013), 104104]. The equation is ut+ 1 2 ( u2 − uu 0−, t x = f ( x, u ( 0−, t )) , x ≤ 0, t > 0. It describes a detonation shock at x = 0 with the reaction zone in x < 0. We inve...

This paper outlines a theoretical approach for predicting the onset of detonation in unconfined turbulent flames. Two basic assumuptions are made: 1) the gradient mechanism is the inherent mechanism that leads to DDT in unconfined conditions, and 2) the sole mechanism for preparing the gradient in induction time is by turbulent mixing and local flame quenching. The criterion for DDT is derived ...

The thermonuclear explosion of a C/O white dwarf as a Type Ia supernova (SN Ia) generates a kinetic energy comparable to that released by a massive star during a SN II event. Current observations and theoretical models have established that SNe Ia are asymmetric, and therefore--like SNe II--potential sources of gravitational wave (GW) radiation. We perform the first detailed calculations of the...

The details of ignition of Type Ia supernovae remain fuzzy, despite the importance of this input for any large-scale model of the final explosion. Here, we begin a process of understanding the ignition of these hotspots by examining the burning of one zone of material, and then investigate the ignition of a detonation due to rapid heating at single point. We numerically measure the ignition del...

BACKGROUND : Injuries from combat and terrorist explosions are increasing worldwide. As such, physicians can expect to treat more patients with complex and unique patterns of injury produced not only by fragments and blunt trauma, but also by high-pressure air expanding from the detonation center. DISCUSSION : Tissue damage from the blast wave or primary blast injury can be an important cause...

Fast self sustained waves of chemical or phase transformations, observed in several contexts in condensed matter effectively result in “gasless detonation”. The phenomenon is modelled by coupling the reaction diffusion equation, describing chemical or phase transformations, and the wave equation, describing elastic perturbations. The coupling considered in this work involves (i) a dependence of...

In the present paper, we report high-fidelity CFD simulation of plume dynamics of a pulse detonation engine (PDE) by using modern parallel computer architecture. The two-dimensional axisymmetric Euler equations for reacting flows are solved by the Space-Time CESE method. A one-step global reaction is employed to model chemical reactions of a propane/air mixture. Computational domain includes th...