Abstract: A family of airfoils for use in a high solidity factor blade having a leading edge portion and a trailing edge portion, a tip portion, and a root portion, has a plurality of airfoil sections. Each section has: one of any of a plurality of camber lines extending from the leading edge portion to the trailing edge portion, the camber lines being scalable relative to each other, each having the same relative shape, the camber lines having a minimal slope from the leading edge to about a 40% chord and an apogee at about a 74% chord; a scalable thickness ratio of between about 2% to about 7.5%; and, a maximum thickness position which is located from about a 37.5% chord for an airfoil at the tip portion of the blade to about a 35.0% chord for an airfoil at the root portion of the blade.

Abstract: A blade has a plurality of relatively thick, super critical airfoil sections, each section having a parabolic leading edge, with a slight camber extending to about a 40% chord, a gradual upper surface pressure recovery region from the 40% chord to the trailing edge, and a concave lower surface from the 40% chord to the trailing edge to generate required lift. The sections, which have a thickness ratio from about 2% to 7.5%, each have a maximum thickness at approximately 0.36 x/c and a maximum camber at approximately 0.74 x/c, wherein x/c is a dimensionless length along the chord of each of said airfoil sections.