A propeller having a central post to which one or more blades are connected. The blades are disposed and configured to pull air in from the propeller's sides toward the propeller's axis of rotation to create pressure in an area in the vicinity of the center of the propeller's rotating axis for generating thrust.
1. A propeller comprising:
a central post coincident with a rotational axis;
one or more separate blades each having a distal end and a proximate end, each blade having an airfoil-shaped cross section;
each of the one or more blades comprising a top section, a bottom section, and a side section, the side section disposed at or toward the distal end;
a length from the central post to the distal end of each of the one or more blade's leading edge is greater than a length from the central post to the distal end of each of the one or more blade's trailing edge such that an outermost foil of the side section is configured to pull fluid inward from the side section of the one or more blades toward the propeller rotational axis by having a non-zero blade angle, wherein the blade angle is defined as the angle between a lateral cross section of a blade and the plane of rotation;
the top section and the bottom section of each of the one or more blades connected at the proximate end to and extending radially outward from the central post;
wherein the top section extends from the central post outward to the side section at a top section distal end and the side section folds back to the central post to a bottom section distal end so a top surface of the top section becomes a bottom surface of the bottom section;
a gap between central post connections of the top section and bottom section of at least one of the one or more blades; and
the one or more blades further configured to pull fluid from a propeller front end to a propeller back end;
wherein the bottom section of the one or more blades forms a more extreme intersection angle with the central post than the top section of the one or more blades forms with the central post, wherein more extreme indicates more toward the vertical.
2. The propeller of claim 1 wherein the one or more blades are in loop form, wherein each of the one or more blades in loop form spins in a same plane of rotation as all other blades of the one or more blades in the loop.
3. The propeller of claim 1 wherein the one or more blades comprise at least one pair of blades opposing one another about the rotational axis.
4. The propeller of claim 1 wherein at least one of the one or more blades is wider at its distal end as compared to its proximate end.
5. The propeller of claim 1 wherein at least one of the blade top section, bottom section or side section of at least one of the one or more blades has a median line that is curved.
6. The propeller of claim 5 wherein each of the top section, bottom section and side section of at least one of the one or more blades is curved.
7. The propeller of claim 5 wherein a twist about the median line of the blade forming a curvature of the blades of the one or more blades is in a range of substantially 30° to substantially 40°.
8. The propeller of claim 5 wherein each blade of the one or more blades is graduated in thickness laterally across the blade.
9. The propeller of claim 8 wherein the one or more blades are graduated in width from a smaller width at the proximate end to a larger width at the distal end.
10. The propeller of claim 1 further comprising one or more additional blades disposed in stacked formation with respect to the propeller.
11. The propeller of claim 1 wherein at least the top and bottom blade sections of the one or more blades exhibit a larger pitch in the vicinity of the rotational axis and a decreasing pitch extending radially outward from the rotational axis.
12. The propeller of claim 1 wherein at least the top and bottom sections of at least one of the blades have substantially linear median lines.
13. The propeller of claim 1 wherein the top blade section of the one or more blades is not symmetrical with the bottom blade section of the one or more blades.
14. A device selected from the group consisting of an aircraft, watercraft, wind turbines, cooling devices, heating devices, automobile engines, and air circulation devices, wherein the device has at least one propeller according to claim 1 .
15. A method of manufacturing a propeller comprising:
selecting a desired direction of fluid flow;
selecting a desired quantity of thrust;
selecting a blade curvature, combination of blades and blade intersection angles to create the selected fluid flow and thrust; and
creating a propeller according to claim 1 with the selected blade curvature and blade intersecting angles.