A System Approach using CartEuler-based Nonlinear Aeroelasticity for FP/LCO Analysis and Design of Control Surfaces

The ZONA Team proposes to develop a nonlinear aeroelastic/aeroservoelastic methodology for free-play (FP)/LCO analysis and prediction for aircraft control surfaces at various trim conditions and subjected to gust/pilot commend excitations. In phase I, a CartEuler-based FP/LCO methodology (CEFM) will be established with a ZONA-developed Cartesian Euler solver fully integrated with a ZONA nonlinear flutter/LCO module (NLFLTR). The Cartesian grid/ boundary condition features of CartEuler allows it to perform rapid but accurate nonlinear aeroelastic simulation for complex aircraft configurations. The CEFM solutions will be validated with wind tunnel test data to be obtained by Duke University with an existing model of typical airfoil section at various FP angle and AoA under gust excitations. Next, using CEFM we will fully investigate various F-16/HT cases, including strained/unstrained structures and under gust/pilot-commend excitations for the impacts of nonlinear aerodynamic and nonlinear structural effects on each free-play and LCO responses from a 3D system perspective. Computed solutions of CEFM for the F-16/HT cases will be compared with those of ZAERO. Based on the computed CEFM results, a useful free-play scaling law will be developed that can be readily applied to establish improved control surface free-play criteria for modern aircraft.