Nonthermal particles can be produced due to incomplete thermalization at collisionless shocks and further accelerated to very high energies via diffusive shock acceleration. In a previous study we explored the cosmic ray (CR) acceleration at cosmic shocks through numerical simulations of CR modified, quasi-parallel shocks in 1D plane-parallel geometry with the physical parameters relevant for t...

Shock tube experiments are a primary means of obtaining ground test data for the hypersonic regime. Accurate characterization gas is crucial to understanding experimental results. However, flows produced behind shock wave has historically proven challenging. This paper applies methodology calculate shocked properties using experimentally recovered speed profile. Static pressure, pitot and heat ...

Different dislocation processes are shown to be operative under high rate loading by impact-induced shock tests as compared with shockless isentropic compression experiments ICEs . Under shock loading, the plastic deformation rate dependence of the flow stress of copper is attributed to dislocation generation at the propagating shock front, while in shockless ICEs, the rate dependence is attrib...

In earlier work we constructed a class of spherically symmetric, ̄uid dynamical shock waves that satisfy the Einstein equations of general relativity. These shock waves extend the celebrated Oppenheimer-Snyder result to the case of non-zero pressure. Our shock waves are determined by a system of ordinary di€erential equations that describe the matching of a FriedmannRobertson-Walker metric (a c...

Using a shock tube to generate shock waves, the wave patterns through several bifurcated junctions were studied. The effect of roughness was simulated by introducing grooves on the lower wall of the junctions, while the upper wall had a smooth surface. Five different bifurcation angles were used in the present study: 0, 30, 45, 60, and 90 degrees. The shock tube driver pressure was P4 = 12 bar,...

Context. Multiwavelength observations of supernova remnants can be explained within the framework of the diffusive shock acceleration theory, which allows effective conversion of the explosion energy into cosmic rays. Although the models of nonlinear shocks describe reasonably well the nonthermal component of emission, certain issues, including the heating of the thermal plasma and the related ...

The study of the interaction of bubbles with shock waves and ultrasound is sometimes termed 'acoustic cavitation'. It is of importance in many biomedical applications where sound waves are applied. The use of shock waves and ultrasound in medical treatments is appealing because of their non-invasiveness. In this review, we present a variety of acoustics-bubble interactions, with a focus on shoc...

Context. X-ray emitting features originating from the interaction of supernova shock waves with small interstellar gas clouds are revealed in many X-ray observations of evolved supernova remnants (e.g., Cygnus Loop and Vela), but their interpretation is not straightforward. Aims. We develop a self-consistent method for the analysis and interpretation of shock-cloud interactions in middle-aged s...

We experimentally study quasi-two-dimensional dilute granular flow around intruders whose shape, size, and relative impact speed are systematically varied. Direct measurement of the flow field reveals that three in-principle independent measurements of the nonuniformity of the flow field are in fact all linearly related: (1) granular temperature, (2) flow-field divergence, and (3) shear-strain ...