Shock Wave Energy: Explosions in Air, Ground, and Water

Abstract

The Shock Wave Energy is a measurable parameter for detonation generated shock waves in air, ground and water. For a medium where the characteristic impedance is quite “constant” (such as geological materials) the energy flux measurement is readily performed by applying the following equation: \( E = \left(\rho c/2\right)\int {u}^2\mathrm{d} t \). Where ρc is the characteristic impedance and u is the particle velocity. For water and air, the energy flux equation is quite similar: \( E = \int {\left(\rho c\right)}^{-1}{P}^2\mathrm{d} t \),where P is the varying pressure along the pressure versus time curve. In air, as compared to water, the technique of measuring the energy flux is complicated by the fact that the characteristic impedance, (ρc), of air varies considerably with pressure. In the body of this paper, the varying values of impedance used while performing this integration as a function of P2 are included. It is now possible to perform computer assisted energy flux measurements for all three of the above media.