Thermochemical Process of Gun Propulsion

Gun propellants burn under conditions of non-constant volume and non-constant pressure. The rate of gas generation changes rapidly with time and the temperature changes simultaneously because of the displacement of the projectile in the com- 

The effective work done by a gun propellant is the pressure force that acts on the base of the projectile. Thus, the work done by propellant combustion is expressed in terms of the thermodynamic energy, f, which is represented by 

The thermal energy generated by propellant combustion is distributed to various non-effective energies.l The energy losses of a caliber gun are approximately as follows  

The remaining part of the energy, 32%, is used to accelerate the projectile. It is obvious that the major energy loss is the heat released from the gun barrel. This is an unavoidable heat loss based on the laws of thermodynamics the pressure in the gun barrel can only be expended by the cooling of the combustion gas to the atmospheric temperature. 

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