The work reported herein was supported by the U.S. Energy Research and Development Administration through the National Science Foundation, and represents an initial evaluation of two innovative wind machines. The first is a vortex concentrator, which is a vertical wing placed in the natural wind in a way that a strong wing tip vortex occurs; a turbine is then placed behind the wing tip in the concentrated energy region of the vortex to convert the energy to more directly-useful forms. The second concept involves a vertical axis turbine with straight blades; the blades are composed of special circulation controlled airfoils which show promise of increasing the overall efficiency of the turbine. Results of approximately the first year's theoretical and experimental investigation are reported, along with conclusions and recommendations for future research efforts.
United States, Energy Research and Development Administration, Division of Solar Energy, "Innovative Wind Machines, Executive Summary and Final Report" (1976). Fuel Sources. Paper 2.