Computational Aeroelastic Simulation of Rapidly Morphing Air Vehicles

摘要

A new approach for computational fluid dynamics-based aeroelastic simulation of rapidly morphing flight vehicles is presented. The morphing vehicle consists of a number of components interconnected by actuators and contact constraints. Due to aerodynamic, inertia!, and actuation loads, the overall structure undergoes large-displacement morphing. The method assumes that each component experiences large rigid-body displacements and small elastic deformations that are linear combinations of the individual normal modes. The structural equations of motion are based on the fictitious-mass substructure modal synthesis method, which is expanded to allow large rotations between the structural components while keeping displacements and rotation compatibility at the interface coordinates. The compatibility equations are time-dependent, and the inclusion of their time derivatives in the equations of motion introduces nonlinear dynamic effects. The resulting generalized-coordinate nonlinear matrix equations of motion are embedded in a time-accurate computational fluid dynamics code. The vector of generalized forces includes aerodynamic forces from the computational fluid dynamics solution as well as inertial and actuation forces. The computational process is demonstrated by two different wing-body configurations where the wings are rotating from parallel to perpendicular positions relative to the body. The morphing simulations demonstrate a robust and stable computational process that exhibits significant aeroelastic effects.