The Equation of State for Gun Propellant Gases under High Pressure

Based on the kinetic theory of molecules and in consideration of high density molecular collision and molecular interaction at high temperature, we propose a simplified model of three molecular collision and introduce the shielding effect of the molecule. In this way, an equation of state of polynomial type is set up that describes the real performance of gun propellant gas under high pressure. We calculated the pressure up to 800 MPa for the gun propellants with different composition. The calculated pressure is in excellent agreement with the experimental data and is better than those calculated by the BLAKE code and used by the US Army.