Adaptive implicit/ explicit finite element methods for axisymmetric viscous turbulent flows with moving boundaries

The extension of the two-dimensional adaptive implicit 1explicit finite elelnent method to axisymmetric turbulent flow problems is presented. Difficulties involved in the selection of proper flow variables for the finite element interpolation to avoid singularities and the treatment of complex source terms resulting from the axisymmetric formulation are covered in this study. A special data structure is proposed for efficiently implementing the PrandtJ-Van Driest turbulence model with an implicit 1 explicit algorithm for adapted unstructured grids. In addition, a moving-grid/eroding-boundary algorithm is implemented (specifically, for modeling the burning of a solid propellant) for internal flow analysis in solid rocket motors. A series of benchmark problems are solved to demonstrate the effectiveness of the methodology.