Curved blade for wind turbines
A curved blade for use on horizontal wind turbines, the blade comprising a substantially semicircular tip portion, a substantially semicircular counter-tip portion opposite the tip portion, and a body portion extending between the tip portion and the counter-tip portion, the body portion being further defined by a concave curved trailing edge and a convex curved leading edge.
1. A curved blade for use on horizontal wind turbines, said blade comprising:
a substantially semicircular tip portion;
a substantially semicircular counter-tip portion opposite said tip portion;
a body portion extending between said tip portion and said counter-tip portion, said body portion being further defined by a concave curved trailing edge and a convex curved leading edge and
a stem coupled to said body portion, for attachment to a respective mounting block located on a rotor of the wind turbine, wherein the stem intersects a chord of the body portion at a midpoint of the body portion.
2. The curved blade according to claim 1 , wherein the chord is constant throughout the body portion of the curved blade.
3. The curved blade according to claim 1 , wherein a maximum chord is located in a midpoint region of the body portion, and decreases in dimension towards each of said tip portion and said counter-tip portion.
4. The curved blade according to claim 3 , wherein the decrease in chord is symmetrical on either side of the midpoint, in the direction of the tip portion and the counter-tip portion of said curved blade.
5. The curved blade according to claim 1 , wherein the longitudinal axis of the stem perpendicularly intersects the chord of the blade at a midpoint of the body portion.
6. The curved blade according to claim 1 , wherein the blade is substantially planar.
7. The curved blade according to claim 1 , wherein the blade is planar and constructed of aluminum plate having a thickness in the range of about ⅛ inch to about ¾ inch.
8. The curved blade according to claim 1 , wherein said stem is covered by a housing that tapers towards each of the leading and trailing edges of the body portion.
9. The curved blade according to claim 1 , wherein said blade is suitable for use at pitch angles ranging from 35 to 45°.
10. A curved blade for use in a blade rotor assembly, said blade comprising:
a substantially semicircular tip portion;
a substantially semicircular counter-tip portion opposite said tip portion;
a body portion extending between said tip portion and said counter-tip portion, said body portion being further defined by a concave curved trailing edge and a convex curved leading edge and
a stem coupled to said body portion, for attachment to a respective mounting block located on a rotor of the wind turbine, wherein the stem intersects a chord of the body portion at a midpoint of the body portion.
11. The curved blade according to claim 10 , wherein the chord is constant throughout the body portion of the curved blade.
12. The curved blade according to claim 10 , wherein a maximum chord is located in a midpoint region of the body portion, and decreases in dimension towards each of said tip portion and said counter-tip portion.
13. The curved blade according to claim 12 , wherein the decrease in chord is symmetrical on either side of the midpoint, in the direction of the tip portion and the counter-tip portion of said curved blade.
14. The curved blade according to claim 10 , wherein the longitudinal axis of the stem perpendicularly intersects the chord of the blade at a midpoint of the body portion.
15. The curved blade according to claim 10 , wherein the blade is substantially planar.
16. The curved blade according to claim 10 , wherein the blade is planar and constructed of aluminum plate having a thickness in the range of about ⅛ inch to about ¾ inch.
17. The curved blade according to claim 10 , wherein said stem is covered by a housing that tapers towards each of the leading and trailing edges of the body portion.
18. The curved blade according to claim 10 , wherein said blade is suitable for use at pitch angles ranging from 30 to 45°.
19. The curved blade according to claim 10 , wherein the blade is planar and constructed of aluminum plate having a thickness of less than ⅛ inch.
20. The curved blade according to claim 10 , wherein the blade is constructed of a material comprising plastic.
21. The curved blade according to claim 20 , wherein the material is glass fibre reinforced plastic.
22. The curved blade of claim 10 , wherein the pitch angle of the blade is less than 35°.
23. A system, comprising:
a plurality of blades, each blade comprising:
a substantially semicircular tip portion;
a substantially semicircular counter-tip portion opposite said tip portion; and
a body portion extending between said tip portion and said counter-tip portion, said body portion being further defined by a concave curved trailing edge and a convex curved leading edge; and
a stem coupled to said body portion of each of said plurality of blades, for attachment to a respective mounting block located on a rotor of a blade rotor assembly, wherein the stem intersects a chord of the body portion of each of said plurality of blades at a midpoint of the body portion.