Development of an Indicial Prediction System for Unsteady Aerodynamic Modeling in Simulation and Design of Maneuvering Fighter Aircraft Co

The goal of the proposed research is to evaluate the use of nonlinear indicia function to efficiently model unsteady aerodynamic responses. Despite the need for enhanced aerodynamic prediction capabilities in flight simulations of maneuvering aircraft, using state-of-the-art solutions of the Navier-Stokes equations remains impractical. Nonlinear indicia theory offers a viable alternative which can fulfill the Air Force's needs for the efficient and accurate modeling of nonlinear "plant" characteristics. The knowledge of these characteristics is a prerequisite for structural response feedback techniques and control system configuration design. In Phase I, a neural network model trained on wind-tunnel data will be used to generate the nonlinear indicia responses associated with a wing undergoing large amplitude maneuvers. The response loads to arbitrary pitch motions will then be compared to those predicted using nonlinear indicia theory. Innovative and efficient methods based on exploiting finite amplitude maneuvers and short-term history effects will also be investigated for parametric modeling of the indicia response. The end product of the Phase I research will be (1) a limited demonstration of the power of nonlinear indicia theory, and (2) the identification of the most promising model parameters for its practical application.