Research

A conceptual multidisciplinary framework is developed for the design and analysis of solar-powered, High Altitude Long Endurance (HALE) flight vehicles. Typical design features such as low wing loading and high aspect ratio imply strong inter-disciplinary couplings, in particular, aerodynamics and structures. A MultiDisciplinary Optimization (MDO) framework is therefore required to fully exploit potential couplings that may result in significant weight savings. In order to rapidly and accurately explore the design space, physics-based first principles are emphasized and reliance on historical or empirical data is minimized. In this paper (Part II), we describe how a solar-powered flying-wing configuration may be optimized using a strategy similar to that described in Part I. A key design driver in this case is the suppression of an aeroelastic phenomenon, “Body-Freedom-Flutter”, resulting from strong modal interactions due to wing sweep. Consequently, for the present study, it is shown that resulting designs are stiffness-driven as opposed to the strength-driven characteristic of conventional configurations (tail-stabilized). In addition, potential benefits of recent progress in active flutter suppression technologies are investigated.