Thin Cambered Lifting Bodies in Ground Effect Flight

Abstract

Ground effect flight uses the ground to block downward dispersion of lift pressures, increasing both lift and lift-drag-ratios (L/D).  For thin-cambered wing sections, L/D increases as the ratio of the wing sections frontal projected height to ground clearance with the ground increases.  This allows thin cambered panels at higher cambers (e.g. 6%) to operate at high L/D with reasonable clearances of water and ground.  Functionally, a thin cambered mid-section of a wing-in-ground (WIG) aircraft delivers more lift per mass than a wing and can replace laterally-extending wings in WIG platforms with frames that allow the tensile strength of the panel to transfer lift forces to the rest of the aircraft.  A catamaran airship design emerges where, with minimal weight penalties, an inboard thin cambered wing is able to: a) increase lift, b) increase surface area for solar power collection, and c) provide a low-resistance path for crossover propulsor benefits in transition from hovering to aerodynamic lifting-body flight.  This paper evaluates the performance of thin-cambered inboard sections for ground-effect machines.