Design analysis methodology for solar-powered aircraft

A methodology for conceptual design of solar-powered aircraft is described. The method is based on traditional design methodologies adapted to address the peculiar characteristics of solar-powered aircraft. The solar propulsion notation is applied to the analysis to create constraint diagrams that have takeoff wing loading ft = Wto/S as their independent variable, and the ratio of solar collector area to reference planform area R — Sce,,/S as their dependent variable. Constraints determined by the propulsion requirements for the design mission of the aircraft define a solution space on the constraint diagram. A design point is selected from within the solution space. Parametric estimates for component weights are then represented as wing loading portions. When these component wing loading portions are summed along with an expression for the required payload wing loading portion, they are equated to the design point wing loading. The resulting equation is solved for the required reference planform area, thus sizing the conceptual design. Three typical conceptual designs are described and analyzed, demonstrating the utility of the methodology.