MultiSCAN 2000 - A Single Switch Developmental Training Aid for Teachers and Students

Not Available This SBIR project proposes to design an optimal methodology for the control of the twintail buffet problem encountered with modern fighter aircraft such as the F/A-18, F-15, and the new joint strike fighter (JSF). The buffet problem occurs when vortices emanating from the leading-edge extension of a delta wing break down before reaching the vertical tails. The resultant Unsteady unbalanced loads on the vertical tails can cause premature fatigue failure. A variety of methods for controlling the buffet problem have been proposed, but none have been definitively demonstrated as being an optimal solution. The proposed effort will utilize a state-of-the-art multi-disciplinary computing environment (MDICE) to evaluate the efficacy of a variety of proposed buffet-control methodologies and to design the optimum methodologies under a variety of flight conditions. MDICE will be configured with a computational fluid dynamics module (CFDFASTRAN), a structure dynamics module, and a conservative-consistent technique for fluid-structure interfacing. A controls module will be added when necessary to model certain active control methodologies. The Phase I effort will demonstrate the feasibility of the computational environment for prediction and control of twin-tail buffet. In this effort, the twin-tail buffet responses of a generic fighter aircraft will be computed and validated against the available experimental data. The effort will then be extended to apply three basic flow control methods under a specified set of flight conditions. Under Phase II, the computational environment will be expanded by developing and evaluating the efficacy of a comprehensive set of flow and structure control methodologies for twin-tail buffet alleviation under a wide range of flight conditions. The resulting optimum methodology or combination of methodologies will then be applied to a real fighter aircraft, e.g. F/ A-18.