Effect Of Variable Burning Rate Propellant Shape On Internal Ballistic Performance Parameters

Variable burning rate propellant was a new type of propellant which can realize high energy and high incremental combustion.It was great significance for its practical application to study the influence law of the shape of the propellant of variable burning rate on combustion performance and interior ballistic performance.In this paper,the 5.8mm standard gun was used as the simulation experiment platform,the combustion characteristics of the layered propellant,spheroidal propellant,granular propellant and layered propellant were studied under the condition of single charge,the results show that the rolling layered propellant with variable burning rate had the characteristic of multiple parameters controlling the energy release law.Through the analysis of the combustion process of different propellant,the physical combustion model was established.Through mathematical derivation,the relationship between the percentage of relative burned mass,the relative burned surface area and the relative burned arc thickness was obtained.Through numerical calculation,it was found that the rolling layered variable burning rate propellant had both the gradual increase of burning rate and the gradual increase of burning surface.The effects of combustion arc thickness,shape structure and combustion ratio on the combustion performance of variable burning rate propellant were studied by using a closed explosive device.The experimental results show that under the same charge condition,the maximum pressure decreases with the increase of the combustion arc thickness of the layered variable burning rate propellant.Among the three different propellant structures,the rolllayered propellant with variable burning rate showed better combustion performance.With the increase of combustion ratio of propellant at variable burning rate,the maximum pressure decreases and the gradual combustion becomes stronger.Under the condition of mixed charge,The maximum pressure decreases with the increase of the combustion arc thickness of the rolllayered variable burning rate propellant when the mixture of the layered variable burning rate propellant is 1:1,and the energy release rule can be controlled.In the experiment,the 5.8mm standard gun was used as the simulation platform,C software was used to program a program which can be used to simulate and calculate the internal ballistic data of the propellant under the condition of single charge.The numerical results show that the maximum pressure in the chamber and muzzle velocity of the gun were directly proportional to the charge amount and fuel ratio of the propellant.The energy of laminar and granular variable burning rate propellant was higher than that of spheroidal propellant when the charge amount is the same.The maximum chamber pressure of the roll-layered variable burning rate propellant was reduced by 15.3%.