Characterization And Analysis Of Propellant Combustion Performance In Electrothermal Chemical Launch Process

The characterization of propellant combustion is used to study the interaction between plasma and propellant in electrothermal chemical gun.In the classical interior ballistic theory,it is assumed that the propellant combustion follows the geometric combustion law,the gas generation function and the interior ballistic equations are established based on this assumption.Different from the classical interior ballistic theory,the potential equilibrium theory is used to analyze the combustion and interior ballistic behavior of propellant in electrothermal-chemical gun.The main contents include:(1)The wavelet threshold denoising algorithm is used to preprocess the measured pressure signal,which provides more accurate experimental data for the subsequent potential equilibrium calculation.The composite evaluation system is established by selecting root mean square error and smoothness,and the wavelet parameters with the best denoising effect are selected according to the Z value of the composite evaluation index.As an example of a closed bomb experiment,the signal de-noising effect is the best when the wavelet basis function is db8,the decomposition level is set to 8,and the threshold method is Birge-Massart strategy.(2)The process of propellant combustion and interior ballistics of electrothermal chemical gun is analyzed by using the theory of potential equilibrium for the internal ballistic,the calculation method of parameters at the potential balance point of electrothermal chemical gun is proposed,the expression of the actual gas generation function of electrothermal chemical gun propellant is given,the increase and decrease of propellant combustion surface is analyzed by using the gas generation intensity,and the interior ballistics similarity equations of electrothermal chemical gun with the potential balance point as the standard state are established(3)The variation regularity of the parameters at the potential equilibrium point of the30 mm electrothermal-chemical gun under different discharge conditions,charge quantity and type of propellant is analyzed,the combustion characteristics of propellant are analyzed according to the fitting gas generating function and gas generation brisance,and the interior ballistic similar equations are calculated to verify the feasibility of the model.The results show that: In a certain range of input electric energy,the gas generation brisance has a good consistency;When the number of discharge modules increases,the actual propellant force increases and the relative burning percentage of propellant at the potential equilibrium point decreases;There is a certain matching relationship between the charge quantity of propellant and the electric energy of the input plasma generator;the combustion enhancement effect of 4/7 propellant is better under the action of plasma.(4)Based on the potential equilibrium theory,the real gas generation function and the burning rate function of the propellant are obtained.The lumped parameter model of electrothermal chemical gun which is more suitable to the actual combustion law of the propellant is established,the calculated curve is compared with the test curve to verify the feasibility of the model.