Experimental Study On The Ignition And Combustion Process Of NEPE Propellants

NEPE propellant has the highest specific impulse among high-energy propellants that has been in application in the world.Its unique composition formula brings it both advantage and disadvantage.On the one hand,it has high energy of double base propellant and good mechanical properties of composite propellant.On the other hand,it has unique combustion mechanism and there is no complete model can be referred to since conventional combustion mechanism of neither double base propellant nor composite propellant can be applied to it.The study on ignition and combustion characteristics of NEPE propellant will benefit the study on its combustion mechanism and provide experimental basis for building and validation of its ignition and combustion models.On the basis of existing study on ignition and combustion of solid propellants,experimental systems are built to study ignition and combustion process of NEPE propellant with different composition formula and particle size distribution.CO₂ laser igniter,high-speed camera and thermocouple are used in the experimental study on the ignition process of NEPE propellant.The ignition process is observed clearly and the temperature is recorded directly.Ignition delay time,ignition temperature and ignition energy can be obtained and the ignition characteristic and mechanism of NEPE propellant are analyzed.Resistance wire is used to ignite NEPE in the combustion chamber.The combustion process and flame characteristic can be observed by high-speed camera.The pressure in the combustion chamber and the temperature of the propellant are recorded during the experiment and burning rate,temperature of combustion surface as well as pressure exponent are obtained to study the influence of pressure,composition formula and particle size distribution on the combustion characteristic.It`s also analyzed which composition and reaction is dominant during the combustion process.Free radical splitting model is applied to simulate the burning rate of NEPE propellant.C++is used to predict the burning rate of NEPE propellants with different composition formula and particle size under different pressures.The simulation results are compared with experimental results to check its feasibility and veracity.