Optimal Dynamic Soaring for Full Size Sailplanes

Abstract : Dynamic soaring is a unique flying technique designed to allow air vehicles to extract energy from horizontal wind shears. Dynamic soaring has been used by seabirds like the Albatross to fly hundreds of kilometers a day across the ocean. Small hobby radio controlled sailplanes have also used this technique to achieve sustained speeds of over 200 miles per hour from just a simple hand toss. Dynamic soaring, however, has never before been studied for use on full size aircraft. The primary goal of this research was to prove or disprove the viability of dynamic soaring for enhancing a full size aircraft's total energy by using a manned sailplane as a demonstration air vehicle. The results of this study will have a direct impact on the sport of soaring, as well as the design of the next generation of large, sailplane-like, robotic planetary explorers for the National Aeronautics and Space Administration (NASA). This research began with a point mass optimization study of an L-23 Super Blanik sailplane. The primary goal of this study was to develop and analyze optimal dynamic soaring trajectories for full size sailplanes. A prototype 6 degrees of freedom (DOF) flight simulator was then developed at the Air Force Research Laboratory's Aerospace Vehicles Technology Assessment and Simulation Branch (AFRL/VACD) and implemented on their Large Amplitude Multi-Mode Aerospace Research Simulator (LAMARS). This simulator helped to validate the dynamic soaring aircraft equations of motion derived for this research and built operational simulator development experience. This experience was then incorporated into a full dynamic soaring research simulator developed at the NASA Dryden Flight Research Facility (NASA DFRC). This NASA simulator was used to develop advanced dynamic soaring flight displays, flight test techniques, and aircrew coordination procedures. Flight test were successfully accomplished using an Super Blanik sailplane and advanced weather monitoring equipment.