Research On Particle Deposition And Internal Insulation Ablation Process In The Secondary Combustion Chamber Of Solid Rocket Ramjet

The particle deposition and insulation material ablation on the wall inside thesecondary combustion chamber of solid rocket ramjet were key problems, which wouldaffect the application of solid rocket ramjet in future missile. In this dissertation, someexploring researches were carried out roundly by the method of theoretical analysis,numerical simulation and direct-connect experiments, with regard to the two phasecoupling, the physical process and mechanism of particle deposition and insulationablation.Based on the classical nucleation theory, al2o3 droplet solidification process in thesecondary combustion chamber of solid rocket ramjet was studied, and the droplettemperature during nucleation and recalescence was calculated. The carbon particlecombustion process in the secondary combustion chamber of solid rocket ramjet wasstudiedusing an improved Moving FlameFront(MFF)model.Taking into account the turbulent dispersion of particles, the two phase flow in thesecondary combustion chamber of an aluminum/magnesium-based propellant solid rocketramjet was numerically simulated,basedonthe stochastic trajectorymodel.Particle-vortexcoupling analysis and particles trajectories were investigated in thesecondary combustionchamber ofsolidrocket ramjet.Twoinfluential vortexes,whichwere thecentervortex andinlet annular vortex, were found. The effect of particles trajectories on flow in thesecondary combustion chamber was investigated. Basis was made for further research onparticledepositionandinsulationablation.Through the analysis of dynamic deposition process, a particle deposition model withhigh speed shear stress was established. By discussing the physical ablative process ofinsulation material, a steady ablation rate method was presented, and the method wasverifiedby the dissection data.By analyzing the deposition distribution on the wall in the secondary combustionchamber with various particles, structural and working parameters, the deposition ratesalong the wall in the secondary combustion chamber were numerically simulated. In theunsteady deposition process the effect on the deposition distribution due to the distortedflow boundary was investigated by the movingmesh technology.The groovenear the inletexit was resolved primely by unsteady deposition process analysis, which providesdeposition reduction valuable information.With the steady ablation rate method, the steady ablation rates three-dimensionaldistribution and ablation mechanism at different positions on the wall in the secondarycombustion chamber were investigated. The effects of different structural and workingparameters on ablation rates, such as particle erosion, thermal chemical ablation etc., wereanalyzed,which provided ablation reduction valuablein formation. The particle deposition and insulation ablation with different structural and workingparameters in thesecondary combustion chamber ofsolid rocket ramjet were investigatedpreliminarily. The particle deposition model and steadyablation ratemethod wereverifiedby the experiment data, which would be helpful for further research on deposition andablation.In this dissertation, many phenomena in the ducted rocket experiment would beinterpreted by the two phase coupling analysis. The particle deposition model and steadyablation rate methodcan be used to make a qualitative analysis of particle deposition andinsulation ablation along the wall in the secondary combustion chamber of solid rocketramjet,which provided future engine designers valuable guidance.