| Single-discipline analysis approaches often utilize linearized descriptions of coupled system physics from other disciplines. When this level of approximation is inadequate for the purposes of the analysis, nonlinear governing equations for the separate physical disciplines must be introduced, thus producing a multiple-discipline analysis. The multiple-discipline approach can provide a deeper understanding of the underlying system physics, and can reveal deficiencies in systems designed by single-discipline means. An advantageous way to examine a nonlinear multiple-discipline system is the partitioned method, where each discipline subdomain is formulated and discretized separately, allowing separate modular solvers for each set of discretized equations. Avoiding ad hoc approaches, a unified approach is developed here and applied to analysis of conjugate heat transfer in an arc-heater wind tunnel nozzle, and fluid-structure interaction of a segmented solid rocket motor inhibitor. The specific systems examined represent actual hardware designed by single-discipline methods. The nonlinear effects present in the wind tunnel nozzle problem include separated, viscous fluid flow, forced-convection boiling, and flow-dependent heat transfer properties. Nonlinear effects present in the solid rocket motor inhibitor problem include large structural deformation, and separated, viscous fluid flow. Steady-state results obtained for the nozzle problem show distributions for wall temperature, fluid temperatures, and heat flux, as well as coolant flow field and recirculation patterns. These results indicate a design deficiency in the nozzle cooling system. For the inhibitor problem, steady and unsteady fields of stress, strain, and displacement are obtained for the structural components, accompanied by velocity and pressure fields for the surrounding gas flow. The large stress values present in the solid propellant suggest a possible mode for motor failure, and beckon examination of a full-configuration model of the Space Shuttle Reusable Solid Rocket Motor. |
