Multi-phase flow field simulation has been performed on solid rocket motor and effect of multi-phases on the performance prediction of the Solid Rocket Motor is investigation. During the combustion of aluminized propellant,the aluminum particles in the propellant melt and form liquid aluminum at the burning propellant surface. So the flow within the rocket motor is multi phase or two phase because it contains droplets and smoke particles of Al2O3. Flow simulations have been performed on a large scale motor, to observe the effect of the flowfield on the chamber and nozzle as well. Uniform particles diameters and Rosin-Rammler diameter distribution method that is based on the assumption that an exponential relationship exists between the droplet diameter, d and mass fraction of droplets with diameter greater than d have been used for the simulation of different distribution of Al2O3 droplets present in SRM. Particles sizes in the range of 1～100μm are used, as being the most common droplets. In this approach the complete range of particle sizes is divided into a set of discrete size ranges, each to be defined by single stream that is part of the group. Roe scheme-Flux differencing splitting based on approximate Riemann problem has been used to simulate the effects of the multi-phase flowfeild. This is second order upwind scheme in which flux differencing splitting method is employed. To cater for the turbulence effect, SpalartAllmaras model has been used. The results obtained show the great sensitivity of this diameters distribution and particles concentrations to the SRM flow dynamics, primarily at the Motor Chamber and nozzle exit. The results are shown with various sizes of the particles concentrations and geometrical configurations including models for SRM and Nozzle. The analysis also provides effect of Multi-phase on performance prediction of Solid Rocket Motor.
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