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/volum e formulation for coupled transient aeroelastic problems is presented. The description includes a rigorous derivation of a geometric conserv ation law for flow problems with moving boundaries and unstructured de formable meshes. The solution of the coupled governing equations with a mixed explicit (fluid)/implicit (structure) staggered procedure is d iscussed with particular reference to accuracy, stability, distributed computing, I/O transfers, subcycling and parallel processing. A gener al and flexible framework for implementing partitioned solution proced ures 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 i nvestigation on an iPSC-860 massively parallel processor of the instab ility of flat panels with infinite aspect ratio in supersonic airstrea ms.