River turbine

In a river current motor of the type made up of a primary nozzle with longitudinal horizontal axis parallel to the river current direction, for collecting a portion of the river current from the mainstream of said current, the said primary nozzle having in sequence along its axis an entrance end connected to a through-going waterway, leading to a throat and then through a tailpiece to a discharge end, and coaxially supporting within the throat an axial entrance turbine wheel to which is connected means for transferring mechanical rotational energy to external utilization means, the improvement comprising the following:

• a. the flaring of the waterway from the throat to the discharge end to initiate and establish a gradually increasing cross-section of the collected portion of said river current from the time it passes said turbine wheel, and
• b. the flaring and structuring of the exterior of said primary nozzle having means to initiate and establish the formation of a diverging conical sheath of mainstream river current around the said collected portion as said portion exits the discharge end of said primary nozzle,
• the provision in the said structuring of a set of radially extending vanes on the exterior surface of said primary nozzle, each vane of said set having a helically bent trailing edge, all said bent trailing edges being turned in the same helical direction, whereby to induce helical rotation into said diverging conical sheath.