Description: Solid rocket motor (SRM) design requires detailed understanding of the slag accumulation process in order to: predict thrust continuity, optimize propellant conversion efficiency, predict coning effects from sloshing, and to assess potential orbital debris (slag) hazard. Current state-of-the-art models for SRM environment do not have the capability to simulate the accumulation and dynamics of slag in SRMs as they rely on a Lagrangian particle approach that are only capable of predicting the location of accumulation. In Phase I, a multiphase framework comprising of gas-phase, a dense slag-phase, and Lagrangian particles representing aluminum and alumina was developed and demonstrated. Phase II effort will focus on extending the developed approach by a) incorporating improved transport and thermal properties of slag, b) improving numerical approach for solving transport of gas and slag-phase in SRM environment, c) enhancing the coupled flow simulation capabilities including accelerated frame of reference to predict slag dynamics and d) providing detailed verification and validation of sub-models and overall simulation capabilities. The tools developed will be of great use in designing and developing next generation SRMs and effect of slag on thrust oscillations, coning and debris prediction.

Benefits: Prediction of slag accumulation during SRM operation, Analysis of slag accumulation effects on propellant conversion efficiency, Prediction of sloshing and the potential effects on SRM conning, Assessment of slag as a potential debris hazard, Support new SRM concept and trade studies analysis

Military application: Prediction of SRM burnout and time at which slag poses as a potential hazard; prediction of thermal signatures associated with slag for both tactical and missile defense. Civilian Applications: Analysis of volcano eruptions and dispersion of hazardous lava; slosh predictions for ships and civil transport applications.