Parallel Multigrid Algorithm for Aeroelasticity Simulations

This paper presents the development of a multigrid parallel algorithm for a nonlinear aeroelastic analysis. The aeroelastic model consists of 1) a nonlinear structural model that captures in-plane, out-of-plane, and torsional couplings; 2) an unsteady viscous aerodynamic model that captures compressible flow effects for transonic flows with shock/boundary-layer interaction; and 3) a solution methodology that assures a tightly coupled solution of the nonlinear structure and the fluid flow, including a consistent geometric interface between the highly deforming structure and the flowfield. A domain-decomposition parallel computation algorithm based on a message-passing interface was developed for the flow solver. A three-level multigrid algorithm was implemented in the flow solver to further reduce the computational time. A grid generation and deformation algorithm was developed concurrently with the flow solver in order to improve the efficiency of the computation. The grid deformation methodology kept the mesh topology unchanged as the structure deformed. Consequently, it was not necessary for either the parallel computation or the multigrid algorithm to update their communication pointers while the structure deformed. The validation of the numerical solver was done using experimental results of the F-5 wing. The aeroelastic solver was then used to assess the effect of structural nonlinearities on the aeroelastic response of the heavy Goland wing.