Model-Based Diagnostics and Prognostics for Solid Rocket Motors

MODIFIED) A progress in development of the physics model based diagnostic and prognostic system for solid rocket motors (SRMs) of the new generation of the crew exploration vehicles is reported. The performance model (PM) of the internal ballistics of large segmented SRMs in the regime of steady burning in the presence of the case breach fault is presented. This model takes into account propellant regression, erosive burning, surface friction, nozzle ablation, and also processes describing faults. The performance of the model is verified by comparison with the results of 2D high-fidelity simulations. Importantly, the PM allows for the simulation of a number of faults observed earlier in large segmented SRMs including nozzle blocking, bore chocking, propellant debonding, and case breach fault. The developed model of the case breach allows calculations of the side thrust at a given location along the rocket axis. The model takes into account the effect of mass addition along the rocket axis, erosive burning, and surface friction. In this paper we illustrate to use the developed PM for analysis of the breach fault. The model of the internal ballistics is combined with the model of dynamics of burning-through case at a given location along the motor axis. The case breach fault diagnostic is developed using algorithm of inference of the case breach area in a quasisteady approximation. The prognostic of the case breach fault is achieved using a scaling algorithm. The diagnostic and prognostic algorithms were verified using the results of the ground firing test of a sub-scale motor. *