Time-Accurate Simulatiion of Moving Bodies Using Unstructured Technology

A robust and accurate extension of an existing state-of-the-art steady-state compressible unstructured flow solver and grid generation package to include time-accurate simulation of multiple moving bodies is proposed. Improvedments to existing algorithms should enable the routine simulation of such problems as aircraft store separation phenomena. A discretization of the time-dependent Navier-Stokes equations will be modified to include the effects of moving grids and arbitrarily high temporal accuracy. Restrictions in maximum allowable time step will be eliminated through the use of an implicit dual-time-step formulation. Preconditioning the compressible Navier-Stokes equations will eliminate stiffness of convergence due to Mach number, Reynolds number and cell aspect ration such that the formulation will be appropriate for very low Mach number and transonic flows. Unstructured discretization of the domain is accomplished with algorithms based upon three-dimensional advancing front technology as well as Delaunay triangulation. Solution accuracy will be improved through the use of global and local element refinement.