Patent 7018166 was granted and assigned to Freegen Research Limited on March, 2006 by the United States Patent and Trademark Office.
The performance of a turbine in a duct having a convergent and a divergent surface is enhanced by controlling the fluid flow pattern along the inner duct surface. For this purpose a free rotor redistributes part of the inner fluid stream through a ring into the outer stream to prevent premature separation of the inner stream from the divergent duct surface. The turbine and rotor are driven by distinct fluid streams that are separated by a duct.