Efficiency of hydrodynamic energy transfer to an arbitrarily thick flat layer of material during pulsed ablation

Abstract

We obtained a general analytical solution of the problem of hydrodynamic energy transfer to a flat layer of material with an arbitrary initial thickness when ablation—the evaporation of material and the formation of a pressure gradient under the action of an external pulsed energy source—takes place at one of its surfaces. The solution was obtained in the form of a dependence of the fraction of the source energy transferred to the nonevaporated part of the layer on the intensity and duration of the energy source as well as on the initial layer thickness and density. The solution includes, as limiting cases, the previously obtained solutions for the hydrodynamic transfer coefficient during the ablation acceleration of a thin layer, through which the travel time of a shock or acoustic wave is much shorter than the duration of the energy source, and for the ablation loading efficiency when a shock wave propagates through a semiinfinite layer.