Study On The Gasbag Inflation Process Of Pyrotechnic Gas Generator

Compared with the traditional gun launch mode,electromagnetic launch technology is a major innovation in the field of information weapons.Based on the above special launch environment and the inflatable suspension function to be achieved by the projectile body,it is necessary to carry out research on the inflatable deployment structure of pyrotechnic gas generator suitable for strong electromagnetic environment.However,because it is difficult to observe the internal response of the gas generator in the ground test,and the airbag inflation process is transient,in order to ensure the stability of the annular airbag in the inflation and deployment process,it is necessary to carry out numerical simulation of the internal ballistics,heat flow field and inflation process of the gas generator.Therefore,the structure of the gas generator is designed in this paper,and it is used as the power source for the inflation and deployment of the annular gasbag.A model for the interior ballistics of the gas generator is developed,and the changes in the gas flow through the nozzle and the temperature of the combustion chamber are determined by solving the model.Use the CV method to model and simulate the inflation and deployment process of the circular airbag,and analyze the changes in various parameters.At the same time,the reaction heat flow field of the gas generator is simulated to verify the correctness of its filter cooling structure.This article mainly includes the following research contents:1.The ballistic program in the gas generator is compiled,and the structure of the generator is designed.Through theoretical calculations,data such as temperature,pressure,percentage of propellant burned,and mass flow rate of the nozzle in the combustion chamber were obtained.Subsequently,the aforementioned data will be utilized as the initial boundary parameters to model the inflation and deployment of the annular airbag.This will encompass the temperature progression of the combustion chamber and the mass flow rate curve of the nozzle.2.A simplified gas generator model was established,and the Fluid Flow(Fluid)module in Ansys Workbench was used to compare and study the four cooling conditions of side exhaust,straight exhaust and filter cooling devices.The temperature of each part of the gas generator in the reaction is analyzed,and the internal heat flow field and temperature distribution are obtained to verify the rationality and necessity of the filter cooling structure.3.Create a flat airbag model using fabric materials and simulate the folding of circular airbags under realistic operating conditions.The temperature and nozzle flow curve of the gas generator under 80 g charge is taken as the inlet boundary condition of the airbag motion simulation.The simulation calculation of the airbag was conducted using the control volume method,and the process of inflation and landing of folded and unfolded airbags at a height of0.5 meters from the water surface was analyzed.4.The ground inflation test was carried out to verify the rationality of the overall design of the gas generator and the integrity of its functions.