A flow enhancement improvement for an underwater turbine generator (10) is disclosed wherein a longitudinal hole (240) is disposed in the central area (26), typically a hub (20) of the generator (10), and a second, augmentor duct (41), preferably rigid, is disposed about the outer duct (40) or housing...http://www.google.fr/patents/US7874788?utm_source=gb-gplus-shareBrevet US7874788 - Flow enhancement for underwater turbine
