Supercritical airfoil design for future high-altitude long-endurance concepts

The design and analysis is presented of a new laminar How airfoil for a future high-altitude long-endurance aircraft that has an operational condition at supercritical speeds. The XFOIL and MSES computational codes were used to design, modify, and analyze the airfoil. The air-foil has enough thickness and performance to meet the requirements set for one of the U.S. Air Force Research Laboratory's SensorCraft concepts: a joined-wing configuration with a diamond shape in planform and front views. This SensorCraft concept's geometry and operational altitudes and speeds were used to determine the airfoil design conditions. The airfoil has a drag bucket over a large range of lift coefficients. Boundary-layer transition location is at about 60% chord upper surface and 70% chord lower surface and is characterized by a laminar separation bubble, which. decreases in size with increasing angle of attack. Sensitivity studies were carried out to investigate the effects of Reynolds number and Mach number, along with boundary-layer transition parameters. Further experimental work needs to be performed to validate the design.