For example, the flight lift-coefficient range is the same as that of the turbulent-flow NACA 23015 airfoil. During the design of this airfoil, special emphasis was placed on experiences and observations gleaned from other successful general-aviation airfoils. The loss in c 1, max due to leading-edge roughness at R = 2.6 × 10 6 is 11% as compared with 14% for the NACA 23015.Ībstract = 'A natural-Iaminar-flow airfoil, the NLF(1)-0115, has been recently designed for general-aviation aircraft at the NASA Langley Research Center. The hinge moment for a 20% chord aileron is fixed at a value equal to that of the NACA 63 2-215 airfoil, C H = −0.0022. The zero-lift pitching moment is held to c m, 0 = −0.055. While this airfoil can be used with flaps, it is designed to achieve a c 1, max of 1.5 at R = 2.6 × 10 6 without flaps. Low-profile drag as a result of laminar flow is obtained over the range from c 1 = 0.1 and R = 9 × 10 6 (the cruise condition) to c 1 = 0.6 and R = 4 × 10 6 (the climb condition). It is designed primarily for general-aviation aircraft with wing loadings of 720–960 N/m 2 (15–20 lb/ft 2). The NASA NLF(1)-0115 airfoil has a thickness of 15% chord. Furthermore, not using aft loading eliminates the concern that the high pitching-moment coefficient generated by such airfoils can result in large trim drag if cruise flaps are not employed.

Also, although beneficial for reducing drag and producing high lift, the NLF(1)-0115 airfoil avoids the use of aft loading, which can lead to large stick forces if utilized on portions of the wing having ailerons.

A natural-Iaminar-flow airfoil, the NLF(1)-0115, has been recently designed for general-aviation aircraft at the NASA Langley Research Center.

Laminar flow airfoil