Research On The Plasma Enhancing Secondary Combustion Of Boron-based Propellant

In order to improve the combustion performance of boron-containing rich-fuel gas in solid ramjet rocket,a new concept of using the plasma to enhance combustion of boron-containing fuel-rich gas was put forward.Based on the theoretical research and experimental study,the enhancing effect of plasma on the combustion of boron-containing rich-fuel gas was verified.And the mechanism of plasma-assisted combustion was obtained.The main work and conclusions are as follows:(1)With analyzing the process of plasma-assisted combustion of boron-containing fuel-rich gas,the mathematical model of gas-solid two-phase combustion and flow is established.In the mathematical model,the strong coupling effect between plasma and combustion dynamics were taken into account.(2)The plasma-assisted combustion experiments of the gas phase component with different air-fuel ratio were carried out,in which,the influence law of plasma on combustion of gas phase component was obtained.Experimental results show that: Under the action of plasma,the reliable ignition and stable combustion of gas phase component of the fuel-rich gas is achieved,and the combustion efficiency can be increased by more than 12%;With the increase of air-fuel ratio,the effect of plasma-assisted combustion is slightly decreased;With the increase of air temperature,the effect of plasma-assisted combustion is significantly increased.(3)The plasma-assisted combustion experiments of boron-containing fuel-rich gas with different discharge power were carried out,in which,the influence law of plasma on combustion of boron-containing fuel-rich gas was obtained.Experimental results show that: Under the action of plasma,the flame structure of boron-containing fuel-rich gas were changed,the ignition position is closer to the front of combustor,the burning surface become larger and the high temperature reaction zone moves forward;The burning heat of fuel-rich gas is increased,the ratio of the increased burning heat and plasma discharge power in the combustion chamber is about 6.5,which improve the combustion environment of boron particles;The combustion efficiency can be increased by more than 5% after the addition of plasma;With the increase of discharge power,the effect of plasma-assisted combustion is significantly increased.(4)Based on mathematical model of gas-solid two-phase combustion and flow,the numerical simulation under typical experimental conditions was accomplished,which were aimed to study the effect of thermal and chemical of plasma on the combustion process of fuel-rich gas.Simulation results show that: Adding the plasma into the boron-containing fuel-rich gas improves the concentration of OH,O and other free radicals effectively,and promotes the chain reaction of boron-containing fuel-rich gas and B,which makes the gas react more fully and the burn heat release more;The temperature of boron particles in fuel-rich gas is increased obviously,the ignition position is advanced,the consumption of boron is accelerated and the combustion efficiency of boron is improved.Using the plasma to enhance combustion of boron-containing fuel-rich gas can provide a new idea to improve the performance of the solid ducted rocket,and the research results will provide references and basis for the application of plasma-assisted combustion technology in the solid ducted rocket.