Conceptual Aircraft Design Studies with Integrated Active Flow Control

Abstract

Active flow control (AFC) technology has been successfully applied to a variety of airfoils and wings for decades. However, this technology is traditionally applied as a “fix” to issues discovered late in the vehicle design process. Since the vehicle cannot be re-sized at this point, the full potential cascading effects of AFC on the vehicle cannot be exploited. The presented work incorporated conceptual design-level aerodynamic and system modules for AFC technology into multiple state-of-the-art multidisciplinary design analysis and optimization (MDAO) sizing frameworks. Design studies were then performed using these frameworks to size a variety of planform types, exploring how low-speed, high-lift applications of AFC impacted vehicle designs compared to vehicles sized without AFC, using the same set of requirements. These studies showed that AFC can significantly reduce max takeoff weight (MTOW) by increasing wing loading, allowing for higher efficiency at cruise and lower overall empty weight. AFC was also found to be an effective constraint alleviator, with it generating the most net benefit when the mission requirements were the most burdensome. For a lambda wing planform, AFC was found to reduce MTOW by 9% and increase wing loading by 24% for the baseline sizing requirements. AFC doubled the baseline MTOW reduction, 18%, when the requirements for takeoff field length and span were decreased by 30% and 12%, respectively. These general, conceptual design-level tools open the possibility for the wider aerospace community to explore how AFC can impact vehicle designs in more flight regimes and applications.