Plume Simulation Of High-Altitude Solid Rocket Motor Considering Phase Transition And Radiation

As a kind of chemical propulsion device,Solid rocket motor has a long history and extensive application.With the development of China's space industry,more and more attention has been paid to the high-altitude solid rocket plume.In particular,the spectral radiation characteristics of solid particles,which account for nearly 30% of the total mass of the plume,are important for both the infrared stealth technology in the military field and the thermal protection of the spacecraft's sensitive surface in the civil area.Rarefied gas-solid two phase flow and thermal radiation of high altitude solid rocket motor plume involve multiple disciplines.Complex flow and heat transfer problems can not be solved effectively by a single method or experiment.At present,the research on the particles in the high-altitude solid rocket motor plume flow field is mainly focused on the gas-solid interaction.There are few studies on the effect of particle transformation,and no literature on the coupling of the flow field and the particle radiation is found.In order to simulate the rarefied gas solid two phase flow.According to the formula deduced by Gallis,the gas-solid two-phase interaction model is established.Based on the classical nucleation and growth theory,the particle phase transition model is established.Monte Carlo method(MC)was used to simulate the generation and transmission process of thermal radiation.In the framework of the DSMC method,using Fortran language program.In this paper,an example in the foreign literature is used to calculate.The results are in good agreement with the literature.Compared with the domestic literature,the accuracy has been significantly improved.When the plume flow field is simulated,the particle size range selected from abroad is generally smaller than that of the domestic ones.The technical route for obtaining the radiation characteristics of particles is suitable for small particle size.In this paper,the MIE scattering theory is used to calculate the absorption factor and scattering factor of the particles,which solves the problem of obtaining the radiation characteristics of large size particles.On the basis of this,the effects of particle size on the flow field structure,relationship between liquid mass fraction and particle temperature and its influence on wall radiant heat flow are studied.The main conclusions are as follows:(1)In the high-altitude solid rocket motor plume,the axial velocity field of the gas exhibits a V-shaped distribution,and the axial velocity of the gas near the axis is low;(2)Phase change has a significant effect on particle temperature,in the recalescence and the cooling controlled by hear transfer process,particle temperature increases,which indirectly affect gas-solid interaction and particle radiation;(3)Radiation in the second half of the flow determines the particle temperature reduction,and in the first half of the flow convection plays a leading role;(4)Particle size and liquid mass fraction together affect the phase transition process.The smaller the particle size,the faster the temperature drop,the faster phase change occurs.The higher the liquid mass fraction,the longer the phase transition.