Study On The Characteristics Of High Pressure Dense Phase Kerosene Steam Carrying Solid Powder Fuel

With the increase of Mach number of solid rocket scramjet,the wall temperature of combustion chamber gradually exceeds the maximum temperature of combustor material.Therefore,thermal protection of the engine is an inevitable demand for future development.The regeneration cooling technology with aviation kerosene as coolant can effectively reduce the engine wall temperature,and in order to give full play to the role of coolant aviation kerosene,a part of kerosene steam after vaporization is heated and vaporized on the wall of combustion chamber can be used to provide support plate flame for the jet of support plate,so as to promote the ignition and combustion of solid fuel;Part of the fuel is used to carry solid powder fuel,and the performance of the engine is improved by reducing the amount of oxidant carrying capacity of the rich gas generator.Therefore,the feasibility of kerosene steam carrying aluminum powder is studied,and the performance of solid rocket scramjet with aluminum hydrocarbon fuel is evaluated.The effects of Al containing hydrocarbon and fuel rich gas on the performance of ramjet were evaluated on a fixed geometry ramjet.It was found that the specific impulse and specific thrust of ramjet increased with the addition of Al containing hydrocarbon.With the increase of mass fraction of Al containing hydrocarbon in the fuel mixture,the specific impulse and specific thrust increased more.With the increase of the solid gas ratio,the specific impulse of the engine decreases with the decrease of the calorific value of the fuel,but with the increase of the chemical ratio of the mixed fuel,the specific thrust also increases.Through the simplified fluidized bed model,combined with the numerical simulation method,the effects of operating parameters and the physical properties of aluminum powder on the transportation characteristics of kerosene vapor carrying aluminum powder were obtained.Euler two fluid model is used to solve the flow information of gas phase and pseudo fluid phase.In this paper,the transport capacity of aluminum powder increases first and then decreases with the increase of particle size,that is,there is an optimal value(30μm)At this time,the conveying capacity is the largest.It is also found that with the increase of fluidizing air volume,the mass flow of material increases,the solid gas ratio first decreases and then increases due to the change of flow pattern,and then decreases when it reaches the maximum value.When the conveying pressure increases,the increase of gas phase mass exceeds the relative increase of solid mass,resulting in the increase of material mass flow and the decrease of solid gas ratio.The mixing of gas-solid two-phase flow in the injector is studied and analyzed.Combined with SST K-ω The effects of gas temperature,pyrolysis rate,particle size and solid to gas ratio on flow mixing were studied by turbulence model and DPM discrete phase fixed orbit model.The results show that gas temperature and pyrolysis rate have little influence on the gas-solid two-phase flow,and the particles have a great influence on the flow field structure in the throat and expansion section of the injector.With the decrease of particle size,the gas-phase Mach number on the axis of the injector decreases,and with the increase of solid-gas ratio,the gas-phase Mach number on the axis decreases.In addition,the larger the particle size,the larger the particle free area downstream of the injector.Finally,the effects of wall transverse jet and parallel strut jet on gas-solid two-phase mixing in supersonic combustor were studied,and the effects of particle size and solidgas ratio on gas-solid two-phase mixing were explored.It is found that the gas-solid twophase mixing is better in the combustor with parallel strut jet,but the residence time of solid particles in the combustor with transverse wall jet is longer.The change of particle size and solid gas ratio has little effect on gas mixing,but increasing particle size is beneficial to improve the residence time of particles in the combustion chamber in both jet modes.