Multi-Point Design and Optimization of an Natural Laminar Flow Airfoil for a Mission Adaptive Compliant Wing

This paper describes the design of natural laminar flow (NLF) airfoil optimized for use with an adaptive structure trailing edge flap. This “Mission Adaptive Compliant Wing” (MACW) provides variable geometry re-shaping of the upper and lower flap surfaces without discontinuities. The airfoil and flap system is designed using a multi-point optimization approach to maximize natural laminar flow for low drag over a wide lift range for application to long-range, long-endurance aircraft. The wide composite “laminar drag bucket” of this airfoil and flap helps endurance aircraft to continuously optimize their wing L/D throughout a mission. The airfoil and flap were flight tested on a wing model mounted on the Scaled Composites White Knight aircraft and demonstrated laminar flow to 50-60% chord for a wide lift range.