Numerical Study of Two-Stage Light-Gas Hypervelocity Projectile Launchers

摘要

A comprehensive theoretical and numerical analysis is presented for predicting the performance and operation of two-stage light-gas hypervelocity model launchers with deformable pistons. Such launchers are often used in aeroballistic and terminal ballistic ranges. This analyis includes a lumped-parameter interior-ballistics model for simulating the burning of the solid propellant in the combustion chamber, a generalized one-dimensional unsteady gas dynamic model for predicting the flow of the light gas, an ideal-viscoplastic extrusion model for representing the piston deformation process, and a friction model for determining the motions of the piston and projectile/sabot package in the pump and launch tubes. The random-choice method (RCM) with operator splitting, non-staggered gridding, variable node spacing, and local-time stepping is used to solve numerically the one-dimensional flow equations. A comparison of numerical results to light-gas gun experimental data demonstrates that the theoretical analysis is valid and capable of simulating the complicated physical processes that occur in these two-stage projectile launchers.