Operator splitting technique with FORCE scheme employed to simulate pressure wave motion inside gun chamber

The work is focused to study the mathematical modeling and numerical simulation of solid propellant combustion during internal ballistics cycle. Here, we have used a reduced single phase model from Baer–Nunziato two-phase flow model for gas and solid mixture of propellant. The model consists of balance equations of mass, momentum and energy with constitutive laws. First ORder CEntred (FORCE) scheme is employed to provide an insight of motion of pressure wave in gun chamber during burning of igniter and solid propellant. The study is performed with the constant emission rate of igniter gases. The burning rate of propellant is expressed as a non-linear function of pressure in terms of pressure exponent. Depending on the pressure exponent three cases are evolved: constant, linear and non-linear rate of burning of propellant. FORCE scheme captures the motion of pressure wave with time and space. The local phenomena of pressure, temperature, velocity, density and rate of burning are demonstrated from breech end to the base of the projectile at different time. The effect of discontinuous pressure on burning dimensions of grain are examined. The non-uniform burning of grain dimensions may result into grain fracture. This study helps in designing the system to avoid such situations.