Techniques for Reduced Order Modeling of Aeroelastic Structures with Deforming Grids

Reduced order modeling (ROM) seeks to make the modeling of aeroelastic behavior practical by reducing computation time for design codes. Deforming grids are often used in aeroelastic problems to account for the deformation of the structure. Proper Orthogonal Decomposition (POD/ROM) is a ROM technique that operates in an index-space for computations, not accounting for changes in grid dynamics, and must be modified to reflect grid deformation properly. As a POD/ROM is developed, fluid dynamics modes are created based on the index relationship between grid points. The modes are then used to recreate the full-order solution. When the relationship between the grid point locations and the index space changes, the created modes are no longer valid because the new grid dynamics are not captured accurately. To investigate and account for the effects of grid deformation on POD/ROM, a new algorithm is developed that incorporates modifications to the usual formulation.