Assessment of the Parameters of a Shock Wave on the Wall of an Explosion Cavity with the Refraction of a Detonation Wave of Emulsion Explosives

At present, studying the parameters of shock waves at pressures up to 20 GPa entails a number of practical difficulties. In order to describe the propagation of shock waves, their initial parameters on the wall of the explosion cavity need to be known. With the determination of initial parameters, pressures in the near zone of the explosion can be calculated, and the choice of explosives can be substantiated. Therefore, developing a method for estimating shock wave parameters on an explosion cavity wall during the refraction of a detonation wave is an important problem in blast mining. This article proposes a method based on the theory of breakdown of an arbitrary discontinuity (the Riemann problem) to determine the shock wave parameters on the wall of the explosion cavity. Two possible variants of detonation wave refraction on the explosion cavity wall are described. This manuscript compares the parameters on the explosion cavity wall when using emulsion explosives with those obtained using cheap granular ANFO explosives. The detonative decomposition of emulsion explosives is also considered, and an equation of state for gaseous explosion products is proposed, which enables the estimation of detonation parameters while accounting for the incompressible volume of molecules (covolume) at the Chapman–Jouguet point.

Steady radiation fronts behind windows

If radiation of constant intensity W ionizes a gas of density ρ1 behind a window, a steady radiation front may be established and the gas will be heated, accelerated, and compressed. The properties of such radiation-induced waves are discussed as a function of the external parameters W and ρ1. With high absorber density ρ1 the radiation front acts like a "leaky piston" accelerating and compressing the neutral gas ahead, and leaving plasma of reduced density behind. This leads to the formation of a precursing shock wave travelling at vshock α (W/ρ1)1/3. The shock develops as a sharp spike near the Jouguet point which requires a sonic speeds a4 α (W/ρ1)J1/3in the ionized gas. With lower absorber density, the radiation front propagates as vr α W/ρ1 and accelerates and compresses the ionized gas at its rear. This plasma is then brought to rest and expanded in a subsequent rarefaction wave.

Magnetogasdynamic deflagration and detonation waves with ionization

The propagation of a one-dimensional combustion wave into a non-ionized gas at rest in the presence of an electromagnetic field is considered when ionization of the gas occurs across either the combustion wave or a preceding shock wave. The electric and magnetic fields in the undisturbed gas ahead of the waves are mutually perpendicular and orthogonal to the direction of wave propagation. It is shown that steady detonation occurs at a point which is analogous to the Chapman-Jouguet point of ordinary gasdynamic combustion theory. Numerical calculations are made of the state of the gas between and behind the waves in two particlar models, in both of which the upstream electric field is zero. The models are then equivalent to magnetogasdynamic phenomena in a perfectly conducting gas. First, the case of steady detonation is studied. Secondly, steady deflagration in a tube, closed at one end, is discussed.