Shockless acceleration of thin plates modeled by a tracked random choice method

A method for accelerating thin metallic plates to hypervelocities has been proposed by G. McCall. In this method, a shock in a propellant generates a strong expansion wave that smoothly accelerates the plate. We have studied the hydrodynamics of this process in one dimension, both analytically and computationally. The metal was modeled as a stiffened gas, and the corresponding Riemann problem was solved. The asymptotic behavior of the solution was determined analytically. The one-dimensional random choice method, modified so that material boundaries are tracked and the spatial mesh is refined locally, was used to compute the flow; comparison with the asymptotic solution demonstrated its accuracy. With this method, shocks that form within the accelerating plate were accurately resolved, so that possible structural damage to the plate could be evaluated.