To study the combustion performance of aluminum-based micro-cell composite fuel aluminum@ammonium perchlorate(Al@AP),in hydroxyl-terminated polybutadiene(HTPB)solid propellant,the Al@AP was added to HTPB solid propell...To study the combustion performance of aluminum-based micro-cell composite fuel aluminum@ammonium perchlorate(Al@AP),in hydroxyl-terminated polybutadiene(HTPB)solid propellant,the Al@AP was added to HTPB solid propellant instead of Al powder and part of AP.Firstly,the ignition and energy performance of Al@AP were investigated and the effects of Al@AP on the combustion,process and mechanical properties of HTPB solid propellant were studied by means of sphere explosion test system,adiabatic oxygen bomb calorimeter test,standard test engine test,residual active Al test,viscosity test,and tensile test.In addition,the combustion mechanism of Al@AP in HTPB solid propellant was analyzed.The results indicate that Al@AP composites offer faster ignition response than simple physical blends,and the heat of HTPB solid propellant increases from 7385 J·g^(-1) to 7834 J·g^(-1) when 21.3%Al@AP was used instead of aluminium powder.The amount of residue decreases from 3.88%to 2.10%in mass fraction,the content of active Al in residue decrease from 6.14%to 2.57%,and the particle size d_(50) of residue decrease from 298μm to 62μm.The combustion efficiency of HTPB solid propellant improves from 94.0%to 94.6%.The mechanical and process properties of HTPB propellant containing Al@AP can satisfy the application.展开更多
The regulation of the burning rate pressure exponent for the ammonium perchlorate/hydroxylterminated polybutadiene/aluminum(AP/HTPB/Al)composite propellants under high pressures is a crucial step for its application i...The regulation of the burning rate pressure exponent for the ammonium perchlorate/hydroxylterminated polybutadiene/aluminum(AP/HTPB/Al)composite propellants under high pressures is a crucial step for its application in high-pressure solid rocket motors.In this work,the combustion characteristics of AP/HTPB/Al composite propellants containing ferrocene-based catalysts were investigated,including the burning rate,thermal behavior,the local heat transfer,and temperature profile in the range of 7-28 MPa.The results showed that the exponent breaks were still observed in the propellants after the addition of positive catalysts(Ce-Fc-MOF),the burning rate inhibitor((Ferrocenylmethyl)trimethylammonium bromide,Fc Br)and the mixture of Fc Br/catocene(GFP).However,the characteristic pressure has increased,and the exponent decreased from 1.14 to 0.66,0.55,and 0.48 when the addition of Ce-FcMOF,Fc Br and Fc Br/GFP in the propellants.In addition,the temperature in the first decomposition stage was increased by 7.50℃ and 11.40℃ for the AP/Fc Br mixture and the AP/Fc Br/GFP mixture,respectively,compared to the pure AP.On the other hand,the temperature in the second decomposition stage decreased by 48.30℃ and 81.70℃ for AP/Fc Br and AP/Fc Br/GFP mixtures,respectively.It was also found that Fc Br might generate ammonia to cover the AP surface.In this case,a reaction between the methyl in Fc Br and perchloric acid caused more ammonia to appear at the AP surface,resulting in the suppression of ammonia desorption.In addition,the coarse AP particles on the quenched surface were of a concave shape relative to the binder matrix under low and high pressures when the catalysts were added.In the process,the decline at the AP/HTPB interface was only exhibited in the propellant with the addition of Ce-Fc-MOF.The ratio of the gas-phase temperature gradient of the propellants containing catalysts was reduced significantly below and above the characteristic pressure,rather than 3.6 times of the difference in the blank propellant.Overall,the obtained results demonstrated that the pressure exponent could be effectively regulated and controlled by adjusting the propellant local heat and mass transfer under high and low pressures.展开更多
文摘To study the combustion performance of aluminum-based micro-cell composite fuel aluminum@ammonium perchlorate(Al@AP),in hydroxyl-terminated polybutadiene(HTPB)solid propellant,the Al@AP was added to HTPB solid propellant instead of Al powder and part of AP.Firstly,the ignition and energy performance of Al@AP were investigated and the effects of Al@AP on the combustion,process and mechanical properties of HTPB solid propellant were studied by means of sphere explosion test system,adiabatic oxygen bomb calorimeter test,standard test engine test,residual active Al test,viscosity test,and tensile test.In addition,the combustion mechanism of Al@AP in HTPB solid propellant was analyzed.The results indicate that Al@AP composites offer faster ignition response than simple physical blends,and the heat of HTPB solid propellant increases from 7385 J·g^(-1) to 7834 J·g^(-1) when 21.3%Al@AP was used instead of aluminium powder.The amount of residue decreases from 3.88%to 2.10%in mass fraction,the content of active Al in residue decrease from 6.14%to 2.57%,and the particle size d_(50) of residue decrease from 298μm to 62μm.The combustion efficiency of HTPB solid propellant improves from 94.0%to 94.6%.The mechanical and process properties of HTPB propellant containing Al@AP can satisfy the application.
基金the support of the National Natural Science Foundation of China grant number 51776175。
文摘The regulation of the burning rate pressure exponent for the ammonium perchlorate/hydroxylterminated polybutadiene/aluminum(AP/HTPB/Al)composite propellants under high pressures is a crucial step for its application in high-pressure solid rocket motors.In this work,the combustion characteristics of AP/HTPB/Al composite propellants containing ferrocene-based catalysts were investigated,including the burning rate,thermal behavior,the local heat transfer,and temperature profile in the range of 7-28 MPa.The results showed that the exponent breaks were still observed in the propellants after the addition of positive catalysts(Ce-Fc-MOF),the burning rate inhibitor((Ferrocenylmethyl)trimethylammonium bromide,Fc Br)and the mixture of Fc Br/catocene(GFP).However,the characteristic pressure has increased,and the exponent decreased from 1.14 to 0.66,0.55,and 0.48 when the addition of Ce-FcMOF,Fc Br and Fc Br/GFP in the propellants.In addition,the temperature in the first decomposition stage was increased by 7.50℃ and 11.40℃ for the AP/Fc Br mixture and the AP/Fc Br/GFP mixture,respectively,compared to the pure AP.On the other hand,the temperature in the second decomposition stage decreased by 48.30℃ and 81.70℃ for AP/Fc Br and AP/Fc Br/GFP mixtures,respectively.It was also found that Fc Br might generate ammonia to cover the AP surface.In this case,a reaction between the methyl in Fc Br and perchloric acid caused more ammonia to appear at the AP surface,resulting in the suppression of ammonia desorption.In addition,the coarse AP particles on the quenched surface were of a concave shape relative to the binder matrix under low and high pressures when the catalysts were added.In the process,the decline at the AP/HTPB interface was only exhibited in the propellant with the addition of Ce-Fc-MOF.The ratio of the gas-phase temperature gradient of the propellants containing catalysts was reduced significantly below and above the characteristic pressure,rather than 3.6 times of the difference in the blank propellant.Overall,the obtained results demonstrated that the pressure exponent could be effectively regulated and controlled by adjusting the propellant local heat and mass transfer under high and low pressures.
