in their review of aircraft performance improvement. The need for this trade-off is echoed by Abbas et al. Although this necessitates reduced wing sweep, the drag reduction more than offsets the reduction in cruise Mach number. In terms of aerodynamic efficiency, both configurations anticipate substantial improvements through achieving natural laminar flow (NLF) on the wing. Both of these concepts target transcontinental mission profiles typified by the Boeing 737 and Airbus A320 with 150+ passenger capacities. Studies sponsored by NASA over the past 10-15 years have yielded novel configurations such as the MIT/Aurora Double Bubble and the Boeing Transonic Truss-Braced Wing (TTBW). If one considers the well-known Breguet range equation, Range = a ∞ ( M L D ) ( 1 T S F C ) ln ⁡ ( W i W f ) simultaneous improvements to the aerodynamic performance ( M L / D), propulsion ( T S F C), and structures ( W i / W f) are required. Achieving the far-term goals of 60-80% reduction requires revolutionary changes to the aircraft configuration. Pursuant to this goal, NASA has defined metrics for near-term (N+1), mid-term (N+2), and far-term (N+3) goals for reduction in fuel consumption relative to a 2005 best-in-class transport aircraft. Studies by the Air Transport Action Group, as reported in the NASA Aeronautics Research Mission Directorate's Strategic Implementation Plan, indicate that improved vehicle efficiency is a key enabler in achieving a net reduction in carbon emissions. Incorporation of this airfoil onto a transonic, truss-braced wing configuration shows strong potential for meeting mid- and far-term goals for reducing aircraft fuel/energy consumption.Īdvanced airfoil design is a key enabling technology for achieving the substantial reductions in aircraft fuel/energy consumption necessary to sustainably meet the ever-growing demands of commercial aviation. The S207 airfoil exhibits a low-speed, maximum lift coefficient in excess of 2.1, and is limited by compressibility effects around the leading edge. Slotted configurations also have benefits for low-speed, high-lift conditions representative of approach. The S207 airfoil exhibits a range-based figure of merit nearly triple that of a turbulent airfoil representative of modern commercial transport aircraft. At these conditions, low drag is predicted to occur between lift coefficients of 0.40 and 0.79. The airfoil is designed for a cruise Reynolds number of 13.2 × 10 6 and it exhibits a drag divergence Mach number exceeding 0.71. The S207, SNLF airfoil has been designed using requirements derived from a transonic, truss-braced wing commercial aircraft configuration. Slotted, natural-laminar-flow (SNLF) airfoils are a novel aerodynamic concept that enable significant performance improvements over conventional, single-element NLF airfoils.

Laminar flow airfoil