Patent attributes
An airfoil section of a propeller for a propulsion device includes a pressure surface and a suction surface, the pressure surface and suction surface intersecting at a leading edge and a trailing edge. The airfoil section has a meanline defined midway between the pressure surface and the suction surface and a meanline angle is defined as an angle between a tangent to the meanline and a centerline of the propeller. The blade has a meanline curvature defined as the slope of a meanline angle with respect to chord fraction along the meanline, and at least a portion of the meanline has a meanline curvature that increases from between approximately 0.1 chord fraction progressing toward the leading edge and at least a portion of the meanline has a meanline curvature that decreases from between approximately 0.1 chord fraction progressing toward the leading edge.