A Hybrid Computational Approach for Control Surfaces with Geometric Proximity

An innovative hybrid computational approach is proposed for constructing and deforming grids for moving and control surfaces with geometric proximity. The proposed approach utilizes a reduced order method (ROM) for deforming unstructured meshes and Overset Cartesian grid method for large deformations.  The unique characteristics of limited Degrees Of Freedom (DOF) for the moving control surface, such as moving flap and weapons door, will be fully utilized through reduced order method, so that the moving body problem is reduced to simple matrix-vector multiplication.  The use of overset Cartesian method will provide the flexibility when dealing with large deformation, deteriorated grid quality, and/or when the gap between two surfaces is closed or opened. The Phase I efforts will focus on the development and testing of each individual component of the proposed methodology including; the nonlinear reduced order method for unstructured deformation of moving control surfaces; the automatic overset Cartesian grid generation for coupling with unstructured grid and for grid topology change;  and the controlling strategy and criteria to switch between the two methods. Also in Phase I, demonstration calculations will be performed to show the effectiveness and feasibility of the proposed approach. In Phase II, the grid deformation due to elastic deformation will be linked together, and  the API development will be invoked, so that the proposed methodology is generic enough to be utilized by a variety of solvers and flow functions. BENEFITS: The proposed composite reduced order method and Cartesian grid is an innovative approach to handle the dynamic meshes with multiple moving bodies in geometrical proximity.  This concept will have wide-ranging implications to the simulation of complex fluid-structure interactions in aerospace and automotive applications. The commercial outcome of this development will be phenomenal as even some of the sophisticated CFD codes lack an elegant framework for mesh handling in moving body and fluid-structure interaction applications.