Mathematical modelling of combustion phenomenon at meduim caliber cannon barrel

During ignition in the combustion chamber inside barrel, the cannons reach very high temperatures and pressures in milliseconds. The combustion process directly affects the pressure value inside the barrel and the core speed. Additionally, the efficiency of combustion varies depending on the physical and chemical properties of the gunpowder in the ammunition. One of the important parameters affecting this situation is the shape of the gunpowder particles. In another case, as a result of using ammunition with the same gunpowder and different filling rates, different temperature, pressure and velocity values are achieved in the same barrel and core. Therefore, combustion efficiency, gunpowder filling amount and gunpowder content affect the temperature and pressure values in the barrel. Depending on these situations, the combustion phenomenon occurring in a medium-caliber gun barrel was examined analytically and numerically within the scope of the thesis study. Depending on the selected weapon and ammunition types, time-dependent pressure, velocity and temperature values inside the barrel were obtained by solving combustion equations with the help of the Mathcad program. These values, calculated according to the gunpowder weight of the selected ammunition and the given initial muzzle velocity value, were recalculated according to a different desired muzzle velocity. After determining the temperatures depending on time and bullet core position inside the barrel, Reynolds, Prandtl and Nusselt numbers were first calculated according to the average temperature. Afterwards, the heat transfer coefficient was obtained. The heat transfer coefficient and the amount of heat passing into the barrel were calculated for a firing cycle. In addition, the self-ignition time, which is critical for the barrel, was determined analytically using Lawton equations. Depending on the values found, the temperature distribution in the barrel cross-section was obtained with the help of the ANSYS program. Analytical calculations have been validated with results in the literature. Different muzzle velocities can be obtained by changing the type and amount of gunpowder with the help of the program created with Mathcad software.