Deforming mesh for computational aeroelasticity using a nonlinear elastic boundary element method

A nonlinear elastic boundary element method (NBEM) approach is developed as an innovative deforming mesh generator for computational aeroelastic simulation. The computational fluid dynamics (CFD) mesh is assumed to be embedded in an infinite nonlinear elastic medium of a hardening material, leading to the formulation of a pseudononlinear elastostatic problem. Whereas the CFD surface mesh is treated as a boundary element model and the CFD flowfield grid as domain sample points, the NBEM approach solves Navier's equations using a particular solution scheme that removes the requirement of the domain integral in the conventional NBEM formulation. The NBEM approach has a unified feature that is applicable to all mesh systems, including unstructured, multi-block structured, and overset grids. An optimization strategy is employed to determine the optimum hardening material properties by minimizing the mesh distortion in the viscous region where grid orthogonality must be preserved. Three test cases are performed to demonstrate the robustness and effectiveness of the NBEM approach for deforming mesh generation.