MIXED EXPLICIT/IMPLICIT TIME INTEGRATION OF COUPLED AEROELASTIC PROBLEMS - 3-FIELD FORMULATION, GEOMETRIC CONSERVATION AND DISTRIBUTED SOLUTION

A three-field arbitrary Lagrangian-Eulerian (ALE) finite element/volume formulation for coupled transient aeroelastic problems is presented. The description includes a rigorous derivation of a geometric conservation law for flow problems with moving boundaries and unstructured deformable meshes. The solution of the coupled governing equations with a mixed explicit (fluid)/implicit (structure) staggered procedure is discussed with particular reference to accuracy, stability, distributed computing, I/O transfers, subcycling and parallel processing. A general and flexible framework for implementing partitioned solution procedures for coupled aeroelastic problems on heterogeneous and/or parallel computational platforms is described. This framework and the explicit/implicit partitioned procedures are demonstrated with the numerical investigation on an iPSC-860 massively parallel processor of the instability of flat panels with infinite aspect ratio in supersonic airstreams.