The Thermo-Gas-Dynamic Model in the Gas Chamber of a Gas-Operated Gun

The paper presents a thermo-gas-dynamic model of the gas chamber of automatic weapons using the gas extraction principle. The problem is solved using the differential form equation of the mass and energy conservations, the volume variation considering the loss of gas flow and the loss of energy due to heat transferring. The results show that the maximum pressure in the gas chamber is about 2.7 times lower than the average pressure in the bore of the AKM assault rifle at the time of the beginning of gas extraction, the impulse of the extraction equipment is a large extent and the energy loss of the powder gases flowing from the bore into the gas chamber is relatively amount. The proposed model can be used for calculating and designing of firearms using the principle of gas extraction.