Study On Low Characteristic Signal Evaluation Method For Solid Propellant

In this dissertation,a research had been made in detail on the radiation mechanism of the solid propellant optical radiation characteristic signal.In the infrared,ultraviolet and visible light bands,the propellants such as double-base propellant,nitrocellulose propellant and HTPB composite propellant were tested and analyzed indoors.Field experiments were conducted on several different formulations of HTPB engines.Aiming at the difficulty of low-feature signal evaluation of solid propellants,this paper proposed a low-feature signal evaluation method——Propellants radiation signature index(PRSI).The PRSI evaluation method is based on the calorific value of the propellant,the mass burning rate,and the light intensity,so the characteristic signals of different propellants can be quantitatively evaluated.The results are as follows:(1)Firstly,according to the infrared emission spectra of the dual-base propellant,nitrocellulose propellant and HTPB propellant,the infrared radiation energy of the three was calculated,and the main radiation source of the propellant was determined by the position of the emission peak.The average infrared radiation energy was calculated.(2)Secondly,the radiation intensity of the dual-base propellant,nitrocellulose propellant and HTPB propellant in the infrared,ultraviolet and visible light bands was measured indoors using correlation spectrometers.The experimental results showed that the infrared radiation intensity of HTPB propellant in the infrared 3μm-5μm band was small,and the radiation intensity in the mid-infrared,ultraviolet and visible light bands was large,which was 3-4 times that of the double-base propellant and nitrocellulose propellant..(3)Then,four kinds of HTPB engines were tested in the field multispectral measurement.It was found that the four formulations of HTPB engine had the highest radiation intensity in the far infrared band and the lowest radiation intensity in the ultraviolet band.And the No.1 HTPB standard engine had the smallest radiation intensity in each spectral band.(4)Finally,the optical radiation characteristic signal index of the solid propellant was calculated and evaluated by the PRSI method.For indoor measurements,the radiation indices of HTPB propellants in infrared(3μm-5μm),infrared(8μm-14μm),ultraviolet,and visible light are 5.66,0.47,0.34,and 0.44,respectively.Then,using the double-base propellant and the nitrocellulose propellant as the standard,the characteristic signal of the HTPB propellant was evaluated by the percentage method;For the field experiment,the radiation index of the HTPB standard engine in the ultraviolet,visible,infrared(3μm-5μm)and infrared(8μm-14μm)bands of the other three formulations was evaluated based on the HTPB standard engine characteristic signal index.This experiment proved that the method can evaluate any solid propellant characteristic signal with a low characteristic signal propellant as the standard.It also provided an evaluation method for the optical radiation characteristic signals of different propellants and their different propellant charge structures.