Stick-to-Stress Dynamic Flight Simulation for Virtual Flight Test

ABSTRACT: ZONA proposes to develop a comprehensive virtual flight test software system by enhancing the capabilities of the ZONA's Stick-To-Stress Dynamic Flight Simulation (STS-DFS)"previously developed under AFRL contractual support. The current STS-DFS combines flight dynamic model and a nonlinear aeroelastic solver constructed based on neural net-based aerodynamic reduced order model (ROM) and a gust ROM to generate in real-time loads and stresses resulting from pilot input commands. These ROMs are generated from ZEUS, a ZONA's Computational Fluid Dynamic software for aeroelastic simulations. The STS-DFS system has been validated with F/A-18 AAW flight test data and will be further validated with F-15 historical flight test data. In Phase I, the ZONA Team will further develop a store ejection load module to allow the prediction of the dynamic loads and response due to the jettisons of stores. This ejection load module will be validated with available F/A-18 flight test data. Also to be added to the STS-DFS is a nonparametric uncertainty modeling module that will consider aircraft-to-aircraft uncertain variations in their mass and stiffness properties to provide an analysis of the entire fleet not simply of a single aircraft. Application of this uncertainty modeling to the F/A-18 response will be carried out. BENEFIT: As a result of the Phase I effort, the enhanced STS-DFS system will be a high fidelity, multi-disciplinary and real time simulation tool where the aerodynamics, structures, propulsion and control system dynamics are tightly coupled together to provide a virtual flight test capability. It can be employed to accurately predict aircraft loads and stresses for improved fatigue lift and mitigate the cost of solving flight test related problems. It also can be used for control law development, maneuvering flight simulation and handling quality assessment with the inclusion of nonlinear aeroelastic effects. The application of the enhanced STS-DFS system to current and future Air Force vehicles, such as F-22, F-35, Global Hawk, Predator, will lead to a reduction of their respective flight tests necessary for certification. With the current, large customer base of ZONA's commercial software for aeroelastic analyses, ZONA can easily bring the STS-DFS to the aerospace market. Because of the unique capabilities of the STS-DFS, we will capture the entire aerospace market and thus making the STS-DFS system the standard method for virtual flight test simulation.