Combustion Properties Of Boron And Combustion Properties Of Boron Propellants

Due to its high calorific value of elemental boron gradually used in fuel rich propellant,boron-based propellant has the quality of high calorific value,high volume calorific value,high specific impulse characteristics,is the most potential one of the solid propellant ramjet engine.The boron propellant is difficult to ignite because of its special particle structure in the ignition process,thus affecting the combustion efficiency of boron,so that its calorific value can not be fully released.The study of improving combustion efficiency and other properties of boron containing propellant is of important guiding significance to our understanding and application of boron-based propellants.By adjusting the AP and boron in the powder mixture ratio,and adding four kinds of additives in the powder mixture(LiF,Mg,PTFE,oxalic acid)as the object and content of adjusting additives in the powder mixture,test its calorific value and combustion efficiency,in order to seek the best ratio of different combustion additives on the combustion performance of boron.Oxalic acid,Mg,PTFE and LiF have effects on improving the combustion efficiency of boron.The effect of adding 2% oxalic acid on combustion efficiency is the most obvious,and the combustion efficiency is 26.4% higher than that of the control group.The above four additives can increase the explosion heat of the mixed powder,the most obvious increase is 102.26% when adding 3%LiF.The energy characteristics of PTPET/AP/B propellant were calculated by the minimum free energy method,The calculation results show that the boron composite solid propellant,PTPET and A3 content is fixed,with the increase of B content in propellant theoretical specific impulse increases and is about 1.67 in AP and B ratio,B content is 30%,the maximum propellant specific impulse.Thereafter,as the content of B continues to increase,the theory specific impulse of propellant drops.Using double solvent method prepared LiF/B and AP/B composite particles,By means of SEM and particle size measurement,the boron containing propellant was prepared by composite particles,the particle size of composite particles was changed by comparison.Boron-propellent with different content of boron was measured by the detonation heat and burning rate of propellant.The comparison showed that the detonation heat and burning rate of propellant prepared by composite particle were improved to a certain extent.The burning rate pressure exponent decreased and the fluidity of the slurry increased,indicating that the combustion properties and technological properties of the boron-propellants are improved by the composite particles.