Parallel two-level methods for three-dimensional transonic compressible flow simulations on unstructured meshes

We discuss our preliminary experiences with several parallel two-level additive Schwarz type domain decomposition methods fur the simulation of three-dimensional transonic compressible flows. The focus is on the implementation of the parallel coarse mesh solver, which is used to reduce computational cost and speed up convergence of the linear algebraic solvers. Results of a local two-level and a global two-level algorithm on a multiprocessor computer are presented for computing steady flows around a NACA0012 airfoil using the Euler equations discretized on unstructured meshes.