Theoretical Analysis And Experimental Study On The Combustion Of Solid Ducted Rocket Scramjet

This paper takes the solid ducted rocket scramjet as the research object,and mainly focuses on the analysis of the gas-solid two-phase combustion process in the supersonic combustion chamber.The main content includes the thermal cycle analysis of the engine working process,the theoretical performance analysis of the engine,the development of the solver based on the Open FOAM platform,the analysis of the supersonic gas-solid two-phase combustion flow field,and the direct ground test of the solid rocket scramjet.First,carry out the thermal cycle analysis of the solid rocket scramjet.The working process of the engine includes the compression process of the intake duct,the expansion process of the isolation section,the combustion process of the supersonic combustion chamber and the expansion process of the tail nozzle.The combustion process adopts the minimum The Gibbs free energy method performs thermal calculations.The flight test data of Hy Shot II was used for verification,which proved the accuracy of the method.Subsequently,the chemical kinetic mechanism was further considered in the combustion process,and the accuracy of the chemical reaction mechanism was verified by the experimental data of mixed gas combustion and particle combustion.At the same time,a one-dimensional steady model was established for the working process of the supersonic combustion chamber,and its feasibility was verified through the ground test of Hy Shot II and the ground test of a solid rocket scramjet.Secondly,based on the developed theoretical tools,the theoretical performance analysis of the solid ducted rocket scramjet was carried out,and the combustion process of the gas-solid two-phase in the supersonic combustion chamber was studied.In addition,the combustion chamber configuration and characteristics of the engine were also studied.The sensitivity of flow conditions,mixing length and fuel-rich gas components was analyzed.The results show that without any turbulence structure,the required combustion time of boron-containing solid propellant is much longer than that of hydrogen and kerosene;the combustion of rich fuel gas produced by boron-containing solid propellant in supersonic flow generally includes two The process,first is the combustion of the combustible gas phase,followed by the combustion of the boron particles,and the combustion time of the boron particles increases with the increase of the particle size;the length of the supersonic combustion chamber is inversely proportional to the combustion time required for the complete combustion of the rich fuel gas.Under the same working conditions,the length of the combustion chamber required by the boron-containing solid propellant is much greater than that required by the hydrocarbon solid propellant;the configuration of the combustion chamber,incoming flow conditions,mixing length,and fuel-rich gas components will all affect Engine performance has an impact.Thirdly,based on the Open FOAM open source CFD platform,a solver suitable for supersonic gas-solid two-phase chemical reaction flow was developed.The Euler method was used to solve the supersonic gas flow field,and the Lagrangian method was used to track solid particles and gas-solid two-phase combustion process.Two-way coupling,verified by three typical examples,proves the feasibility and accuracy of the solver.Subsequently,the solver was used to analyze the supersonic gas-solid two-phase combustion flow field,and the effects of gas-solid two-phase mass ratio,rich fuel gas equivalent ratio,solid particle types and gas-phase components on the flow field structure and combustion characteristics were studied.influences.In addition,based on the results of theoretical analysis,the influence of the turbulence structure that shortens the mixing length and promotes mixing and combustion on the flow field structure and combustion characteristics is studied.Three common physical structures are mainly used: diagonal wedge,support plate and cavity.The research results show that the above three turbulence structures are all helpful to promote blended combustion,but reasonable design dimensions are required.Finally,based on the calculation results of the theoretical analysis and the simulation results of the supersonic gas-solid two-phase combustion flow field,the engine configuration was designed,and the ground direct connection test was carried out.The windowed combustion chamber was used to observe that the diagonal split was used as the turbulence structure.The evolution of the ignition process.The effects of different turbulence structures and different solid propellants on the engine performance are studied.At the same time,calculations and numerical simulations of the one-dimensional model of the combustion chamber are carried out based on the test conditions to further verify the accuracy of the above method.The research results show that both the diagonal split and the support plate help to promote the blended combustion,and the combustion efficiency can be increased from 0.12 to 0.60,but these two turbulent structures have a great thermal protection pressure;the type of solid propellant has an impact on the engine performance Certainly,the low temperature of rich fuel gas will cause significant ignition delay.