Shock wave/fire interactions initiated by high explosives have been historically demonstrated as potentially effective ways to control oil well fires or even forest fires in situations where conventional means cannot be applied. However, the mechanisms by which a fire can be extinguished by a shock wave are not well understood. A series of experiments have been conducted involving a moving shoc...

Experiments and numerical simulations were carried out in order to investigate the focusing of a shock wave in a test section after the incident shock has been diffracted by an obstacle. A conventional shock tube was used to generate the planar shock. Incident shock Mach numbers of 1.4 and 2.1 were tested. A high-speed camera was employed to obtain schlieren photos of the flow field in the expe...

The question of why the unemployment rate takes a long time before it reverts back to its natural-rate following a negative exogenous shock has been the subject of unremitting interest in macroeconomics. This paper shows that the speed of adjustment to the steady-state unemployment and the degree of risk-aversion in firms are positively related. The reason is that risk-aversion in firms creates...

There is currently little feedback as to whether kidney stones have fractured during shock wave lithotripsy. Resonant scattering of the lithotripter shock wave was used here to differentiate intact and fractured stone models in water. Scattering, including reflection and radiation due to reverberation from within the stone, was calculated numerically with linear elasticity theory and agreed wel...

We find the expectation value of the energy-momentum tensor in the CFT corresponding to a moving black hole in AdS. Boosting the black hole to the speed of light, keeping the total energy fixed, yields a gravitational shock wave in AdS. The analogous procedure on the field theory side leads to “light cone” states, i.e., states with energy-momentum tensor localized on the light cone. The corresp...

INTRODUCTION TO AIR BLAST MEASUREMENTS An explosion in air is a process by which a rapid release of energy generates a pressure wave of finite amplitude. The energy source can be anything that generates a violent reaction when initiated. This includes: chemical or nuclear materials, gases (high pressure gasstorage vessels, steam boilers), or electricity (spark gap, rapid vaporization of a metal...

From the physical point of view a shock wave is defined by an abrupt, nearly discontinuous change in pressure and by having a velocity that is higher than the speed of sound in the medium it propagates [1]. A typical pressure profile of a focused shockwave used for therapeutic purposes is shown in fig. 1. Generally a shock wave can be described as a single pulse with a wide frequency range (fro...

The idea of this work is to compare a new positive and entropy stable approximate Riemann solver by Francois Bouchut with a state-of the-art algorithm for astrophysical fluid dynamics. We implemented the new Riemann solver into an astrophysical PPM-code, the Prometheus code, and also made a version with a different, more theoretically grounded higher order algorithm than PPM. We present shock t...

This paper is concerned with the dynamics of an elastic bar that can undergo reversible stress-induced phase transformations. We consider a Riemann problem in which the initial strains belong to a single metastable phase and prove uniqueness of solution that satisfies a nucleation criterion and a kinetic law at all subsonic and sonic phase boundaries. This paper generalizes the results of [3]; ...