ENERGY-BASED DESIGN METHODOLOGY FOR AIR VEHICLE SYSTEMS: AERODYNAMIC CORRELATION STUDY

This fundamental study served to formulate and predict numerically the performance of a flexible wing in subsonic flow conditions in terms of entropy generation. The developed approach was a joint effort with AFRL personnel in energy-based design. The work represents a new and different approach for detailed drag estimation and vehicle-level utilization of energy. The exergy utilization of a wing in a steady, low subsonic, three-dimensional, viscous flow field was modeled. This amounted to estimating the entropy generation due to the lift and the components of drag of the wing. Wing performance was evaluated for three different wing lift distributions on a rectangular, flexible wing. The power required to overcome wing drag is directly proportional to the entropy flux across the wing. In this study, methods for evaluating both the drag and the entropy flux for a wing based the predictions of a three-dimensional, turbulent computational solver were compared to estimates based on experimental airfoil data and lifting line theory predictions. Overall, we show: (1) the mapping of entropy generation clearly details regions of irreversibility in the wing flow field, and (2) under the limited conditions studied, the drag predictio