Simulation Strategy of Turbulent Internal Flow in Solid Rocket Motor

A strategy for the simulation of turbulent internal flows in a solid rocket motor (SRM) is described. Sources of turbulence inside an SRM are identified and their dominance relative to each other is characterized to set a priority in the modeling effort. This complex problem is simplified by subdividing it into problem components allowing for a more detailed study of each component. Problems of interest in which investigations have been pursued are compressible periodic rockets, spatial transition in a laboratory-scale rocket, and effect of inhibitors and large-eddy simulation (LES) wall-layer modeling (WLM) for the nozzle boundary layer. Grid sensitivity is observed in the application of dynamic LES to a transitional flow in an SRM. Inhibitors at the segment juctions act as a trip in the transition to turbulence and play a more dominant role compared to the injection of turbulence from the propellant surface. Detached-eddy simulation provides relatively accurate wall gradient properties and is more generally applicable than WLM. This hybrid method, however, requires some degree of implicitness in the time discretization to be efficient.