Modelling of Cook-off Experiment for Small Arms Propellant in a Cooling Barrel Using Finite Element Analysis

Abstract

Finite element (FE) analysis is a powerful engineering tool which can be used to solve a heat transfer problem in a complex geometry and assembly. In this paper FE modelling of a cook-off experiment apparatus is presented. The experiment apparatus is used to represents a cook off analysis for a propellant charge inside an unconfined 7.62 mm brass cartridge case surrounded by a hot barrel which is naturally cooled by convection. A 2D axisymmetric FE analysis based on a 3D CAD model of the actual experiment apparatus assembly is carried out. The kinetic parameters of the propellant are applied into the analysis in the form of tabular data as the heat generation input. It is shown that by using proper input parameters for the apparatus and decent curve fitting of kinetic parameters for the propellant inside the cartridge case, a good agreement with the time to cook-off data from experimental results can be achieved. The time to cook off in a hot barrel is important and critical for operational success.