Study On A New Method Of Combustion Performance Test And Interior Ballistics Simulation Of Propellant

In this paper, new methods of the digital filter, heat loss modification and the expression of data processing in propellant burning performance tests were studied in order to improve the deficiency of the existing method of testing, data processing and calculation method. Meanwhile, heat loss in the gun barrel and the calculation method of the interior ballistics based on the propellant burning gases generation rules were researched.In order to slake the noises from pressure signal obtained from the closed bomb tests and express the burning property of propellant more actually, a FI-LS digital filter which combines with FIR lowpass filter and least squares filter was researched, and a new p-t digital filter method was proposed. Analyzing the characteristic of heat transfer between the propellants burning gases and the inner wall, and focusing on the phenomenon of rapid pressure change in closed bomb tests, a heat flux equation considering the pressure change as a factor was raised. The heat transfer function in the test was deduced, and a one-dimensional semi-infinite heat transfer model in the closed bomb test was established. Based on the FI-LS digital filter and the heat loss modification, an n～p curve method were proposed in order to describe the relationship between the propellants burning rate pressure exponent and the pressure, and a visual basic software for propellants combustion performance test was compiled. This paper also studied the combustion characteristics of the multi-perforation propellants. The effect of the aperture change on the propellant burning rate and burning rate pressure exponent was analyzed when propellants were burning, and the burning performance of different length multi-perforation propellants were studied, a asynchronous combustion theory which was closer to the burning characteristics of short multi-perforation propellants was proposed. As it’s difficult to determine the heat loss modification degree when calculating the interior ballistics performance of propellants charge, a heat transfer calculation method in the gun chamber were proposed based on the closed bomb test. According to the pressure and time signals, and the relationship between the pressure and work capability of propellants burning gases in a closed environment, an equation of heat transfer between the propellant burning gases and the chamber wall was given. Based on the interior ballistics equations and heat transfer equation, an interior ballistics simulation model which considered the heat loss in the gun chamber was established. The burning performances of the multi-perforation propellants were studied through the interrupted combustion test and the closed bomb text. A method was raised to characterize multi-perforation propellants burning gases generation rule by using the relationship betweenΨand It, and according to the equation of heat transfer between the propellants burning gases and the chamber wall, a new interior ballistics model which considering the heat loss and burning gases generation rule was built, and the corresponding interior ballistics simulation program was also compiled.The study productions are significant to improve the understanding for actual burning performance of propellant and promote the development of propellant charge technology.