Fluid flow energy converter

Apparatus for extracting energy from the kinetic energy of an unbounded fluid flow such as wind or water, making use of an array of helicoids, characterized by

• (a) the helicoids having all the same pitch angle of between 5.degree. and 36.degree. and having their axes arranged in one plane and parallel to one another,
• (b) the spacing of the axes being so chosen that the outer diameters of adjacent helicoid structures overlap, so that the helicoid sheet of the second helicoid structure gets positioned in the open spaces between the sheet of the first helicoid structure, the sheet of the third gets positioned in the open spaces between the sheet of the second, and so forth, so as to present a long, nearly dense looking array to the fluid flow,
• (c) means for coupling and synchronizing the rotation of all said helicoil structures, so as to secure the mutual position of said helicoid sheets in their respective spatial relationship as just described, and means to couple their rotation to a common output shaft to which they then deliver their energy, said output shaft being coupled to a device doing useful work,
• (d) means securing an appropriate angular relationship between the fluid flow vector and the axis of the helicoids, namely so that the flow vector and a radius vector at right angles to the axes of the helicoids form an angle between them of the same order as the pitch angle of the helicoid, so that essentially only one side of the helicoid sheets is impacted by the fluid flow, at an angle to the normal of the sheet surface, thus deflecting the flow without stopping it completely, the helicoid thereby being set in rotation by the recoil forces, as well as on account of the fluid dynamic negative pressure forces generated on the opposite sides of the helicoid sheets by that part of the flow which passes through the structure.