Research On The Comprehensive Characteristics Of The Jet Fuel System Based On Supersonic Nozzle

Solid rocket engine has the characteristics of simple structure and easy to use,but its specific impulse is low,and the gas contains a lot of H2 and CO which is not fully burned.In order to improve the efficiency of solid rocket motor combustion,the fresh air injection nozzle expansion section,and contains a lot of burning H2,CO,and metal particles of high temperature secondary burning gas to increase the thrust and combustion efficiency,by studying the flow field structure and combustion forms,for effective utilization of solid rocket combustible gas in the energy and further improve the engine specific impulse to lay the foundation.In this paper,the experimental scheme of supersonic supplementary combustion in nozzle expansion section is designed to analyze the combustion status of the supplementary combustion chamber under the condition of injecting high temperature air in nozzle expansion section.Then,the supersonic nozzle supplementary combustion experiment was used as a model,the turbulence model and the finite rate vorticity dissipative combustion model were adopted,and the general computational fluid dynamics software CFX was used to simulate the two-phase combustion flow in the experimental conditions.By comparing the numerical simulation results with the experimental data,the correctness of the numerical simulation results is verified,which lays a foundation for the systematic study on the influence of the supplementary combustion characteristics of supersonic nozzle under different intake conditions.Finally,the orthogonal experiment method was used to design the simulation scheme to study the influence of expansion Angle,intake Angle,air-fuel ratio and intake position of the main nozzle on the supplementary combustion characteristics of the supersonic nozzle,and a better experimental model was obtained.The research results show that:1)Combustion-rich gas containing aluminum metal particles can be blended with air jet in the nozzle expansion section to obtain thrust gain,which verifies the feasibility of supplementary combustion device for supersonic nozzle.2)The supplementary combustion device for supersonic nozzle can effectively improve the combustion efficiency of gas,but there are still a large number of gas that are not fully reacted to the nozzle outlet discharge.With the increase of total inlet air pressure,the average flow Mach number,thrust and specific impulse increase,and the combustion efficiency of gas and aluminum particles increases.Increasing the total inlet air pressure can effectively improve the performance of the nozzle combustion device.3)The inlet position of the inlet has the greatest influence on the supplementary combustion effect of the supersonic nozzle,while the expansion ratio of the main nozzle has the least influence on the supplementary combustion effect.The air-fuel ratio and the intake Angle have similar influence on the containment and combustion efficiency of the supplementary combustion,while the intake Angle has a slightly larger influence factor.4)With the increase of the expansion Angle of the main nozzle,the combustion efficiency of combustible gas is in an upward trend;With the increase of the air-fuel ratio,the combustion efficiency of combustible gases and particles increases greatly.When the inlet Angle increases,the air incidence depth increases,and the combustion efficiency of gas and particles increases.With the increase of inlet position,the closer the inlet is to the back of nozzle expansion section,the combustion efficiency of combustible gas increases.