U.S. patent application number 13/194058 was filed with the patent office on 2011-11-24 for wind turbine blade.
This patent application is currently assigned to GENERAL ELECTRIC COMPANY. Invention is credited to Peter James Fritz.
Application Number | 20110286852 13/194058 |
Document ID | / |
Family ID | 41119615 |
Filed Date | 2011-11-24 |
United States Patent
Application |
20110286852 |
Kind Code |
A1 |
Fritz; Peter James |
November 24, 2011 |
WIND TURBINE BLADE
Abstract
Disclosed is a blade including a blade body including a leading
edge and a trailing edge, and at least one trailing edge cavity
defined by a blade area disposed in at least partial alignment with
the trailing edge, the at least one cavity extending a desired
depth into said blade body in a direction of the leading edge.
Inventors: |
Fritz; Peter James;
(Greenville, SC) |
Assignee: |
GENERAL ELECTRIC COMPANY
Schenectady
NY
|
Family ID: |
41119615 |
Appl. No.: |
13/194058 |
Filed: |
July 29, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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12239465 |
Sep 26, 2008 |
8016568 |
|
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13194058 |
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Current U.S.
Class: |
416/223R |
Current CPC
Class: |
Y02E 10/721 20130101;
Y02E 10/72 20130101; F05B 2240/301 20130101; F05B 2260/97 20130101;
F03D 1/0633 20130101 |
Class at
Publication: |
416/223.R |
International
Class: |
F01D 5/14 20060101
F01D005/14 |
Claims
1. A blade comprising: a blade body including a leading edge and a
trailing edge, said trailing edge being disposed at an edge area of
said blade body that is thinner than a thickest area of said blade
body; and at least one trailing edge cavity defined by a blade area
disposed in at least partial alignment with said trailing edge in
proximity to said edge area, said at least one cavity extending a
desired depth into said blade body in a direction of said leading
edge.
2. The of claim 1, wherein said at least one cavity is a concavity
that is concave into said blade body in a direction of said leading
edge.
3. The blade of claim 2, wherein said concavity includes a
curvature that extends in a longitudinal direction relative to a
longitudinal extent of said blade body.
4. The blade of claim 2, wherein said concavity includes a
curvature that extends in a circumferential direction relative to a
circumferential area of said blade body.
5. The blade of claim 2, wherein said concavity includes a
curvature that extends in a longitudinal direction relative to a
longitudinal extent of said blade body and a curvature that extends
in a circumferential direction relative to a circumferential area
of said blade body.
6. The blade of claim 1, wherein said trailing edge includes a seam
line that is interrupted by said at least one cavity.
7. The blade of claim 1, wherein said at least one cavity is
disposed between a root end and a tip end of said blade body.
8. The blade of claim 1, wherein said at least one cavity is
multiple cavities that are each distinct from each other, and are
disposed between a root end and a tip end of said blade body.
9. The blade of claim 1, wherein said at least one cavity is two
cavities disposed longitudinally parallel to each other, said two
cavities adjoining at a seam line of said trailing edge.
10. The blade of claim 9, wherein interior edges of said cavities
are disposed along said seam line, and extend a greater distance
away from said leading edge than opposing exterior edges of said
regions of concavity.
11. The blade of claim 1, wherein said at least one cavity is at
least one depression including a depressed surface that is disposed
to include at least one of a length and width relative to said
trailing edge.
12. The blade of claim 11, wherein said at least one depression
includes a consistent depth across a length of said at least one
depression.
13. The blade of claim 11, wherein said at least one depression
includes a consistent depth from said trailing edge across a width
of said at least one depression.
14. The blade of claim 11, wherein said at least one depression is
disposed orthogonally to a chord of said blade body, and wherein
said at least one depression is disposed orthogonally to at least a
portion of a longitudinal extent of said blade body.
15. The blade of claim 11, wherein said at least one depression
includes a depression surface disposed at a depth into said blade
body, said depth surface including a concavity into said blade body
in a direction of said leading edge, said concavity including at
least one of a curvature that extends in a longitudinal direction
relative to a longitudinal extent of said blade body and a
curvature that extends in a circumferential direction relative to a
circumferential area of said blade body.
16. The blade of claim 1, wherein said at least one cavity is
triangular in shape, said triangular shape being defined by at
least two sloping surfaces sloping along a length of said at least
one cavity.
17. The blade of claim 1, wherein said at least one cavity is
triangular in shape, said triangular shape being defined by at
least two sloping surfaces sloping along a width of said at least
one cavity.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 12/239,465 filed on Sep. 26, 2008, which is
herein incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The disclosure relates generally to a wind turbine blade,
and more particularly to a trailing edge geometry of a wind turbine
blade.
BACKGROUND OF THE INVENTION
[0003] Wind turbine blades can be manufactured to include a large
width or airfoil chord length. Larger and wider blades can be more
efficient, but the excess width makes it difficult to form the
blade into a cylinder at the root connection. Chord length distance
can be truncated by removal of a part or all of the trailing edge
of a blade. Typically, this truncation is performed via a straight
"chop" or a small fillet to the trailing edge, leading to one ore
more convex or flat areas. Unfortunately, flat or convex truncation
of this kind can lead to difficulties in manufacturing a wind
turbine blade.
[0004] Accordingly, a blade geometry that could reduce chord length
while reducing difficulty of blade manufacture and maintaining
blade strength would be desirable.
BRIEF DESCRIPTION OF THE INVENTION
[0005] Disclosed is a blade including a blade body including a
leading edge and a trailing edge, and at least one trailing edge
cavity defined by a blade area disposed in at least partial
alignment with the trailing edge, the at least one cavity extending
a desired depth into said blade body in a direction of the leading
edge.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The subject matter which is regarded as the invention is
particularly pointed out and distinctly claimed in the claims at
the conclusion of the specification. The foregoing and other
objects, features, and advantages of the invention are apparent
from the following detailed description taken in conjunction with
the accompanying drawings in which:
[0007] FIG. 1 is a perspective view of an exemplary embodiment of a
wind turbine blade;
[0008] FIG. 2 is a cross sectional slice of the blade of FIG. 1
taken along phantom line II;
[0009] FIG. 3 is a partial cross sectional elevation view of the
blade of FIG. 1 taken along 3-3;
[0010] FIG. 4 is a planar view of the wind turbine blade of FIG.
1;
[0011] FIG. 5 is a planar view of the wind turbine blade including
multiple regions of concavity or depression;
[0012] FIG. 6 is a perspective view of another exemplary embodiment
of a wind turbine blade;
[0013] FIG. 7 is a partial cross sectional elevation view of the
blade of FIG. 6 taken along 7-7;
[0014] FIG. 8 is a perspective view of another exemplary embodiment
of a wind turbine blade;
[0015] FIG. 9 is a cross sectional slice of the blade of FIG. 8
taken along phantom line VIII;
[0016] FIG. 10 is a partial cross sectional elevation view of the
blade of FIG. 8 taken along 10-10;
[0017] FIG. 11 is a partial cross sectional view of another
embodiment of a wind turbine blade;
[0018] FIG. 12 is a partial cross sectional view of another
embodiment of a wind turbine blade;
[0019] FIG. 13 is a partial cross sectional elevation view of
another exemplary embodiment of a wind turbine blade; and
[0020] FIG. 14 is a cross sectional slice of another embodiment of
a wind turbine blade.
[0021] The detailed description explains embodiments of the
invention, together with advantages and features, by way of example
with reference to the drawings.
DETAILED DESCRIPTION OF THE INVENTION
[0022] Referring to FIGS. 1-14, a wind turbine blade 10 including a
trailing edge cavity 12 is illustrated. In the exemplary embodiment
of FIGS. 1-4, the cavity is a concavity 12 including a curved
surface or surface. As shown in these FIGS. 1-4, the blade 10 is
defined by a blade body 14, which includes a leading edge 16,
trailing edge 18, a root end 20, and a tip end 22. The concavity 12
is defined by an area 24 disposed along the trailing edge 18. As is
shown best in FIG. 4, this area 24, and thus the concavity 12 the
area 24 defines, is disposed along the trailing edge 18 in such a
way that it interrupts a seam line 26 or relative apex of the
trailing edge 18. Disposal of the concavity 12 along the trailing
edge 18 in this manner effectively creates two trailing edges 18a
and 18b (which are best illustrated in FIG. 3) within the area 24,
which (during blade operation) allows for separation of eddy
currents from both sides of the blade 10, resulting in reduced drag
and higher turbine output efficiency.
[0023] As is shown in FIGS. 1-3, the concavity 12 includes a
curvature 28 that extends into the blade body 14 in a direction of
the leading edge 16. As is best shown in FIG. 2, this curvature 28
may be configured to extend in a longitudinal direction 27 relative
to a longitudinal extent 29 of the blade body 14. That is, the
curvature 28 of the region of concavity starts, curves to its
maximum depth, and terminates along a length of the blade body 14.
As is best shown in FIG. 3, the curvature 28 may also be configured
to extend in a circumferential direction 30 relative to a
circumferential area 31 of the blade body 14. That is, the
curvature 28 of the region of concavity starts, curves to its
maximum depth, and terminates along a circumference of the
circumferential area 31 of the blade body 14. Of course, as is best
shown in FIG. 1, the concavity 12 may also include curvatures 28
are disposed to curve in both directions discussed above.
[0024] As is also shown in FIGS. 1-4, the concavity 12 is disposed
between the root end 20 and tip end 22 of the blade 10. Though it
is not illustrated, it should be appreciated that longitudinal
extents of the concavity 12 may extend from the root end 20 to the
tip end 22. It should also be appreciated that, in exemplary
embodiment, a depth of the concavity 12 will extend from 0.2 mm to
2500 mm for a blade up to 100 m in span. Additionally, as shown in
FIG. 5, there may be multiple concavities 12 that are distinct from
each other, and aligned end to end along the trailing edge 16
between the root end 20 and tip end 22.
[0025] Referring now to FIGS. 6 and 7, the blade 10 may also
include multiple concavities 12 aligned longitudinally parallel to
each other. Each of the concavities 12 includes opposing exterior
edges 32 and interior edges 34. The interior edges 34 meet at a
point of adjacency 36. In the exemplary embodiment of FIGS. 6 and 7
(an as is best shown in FIG. 7), the point of 36 is linearly
continuous with the seam line 26 of the trailing edge 16. As is
additionally evident from the exemplary embodiment of FIG. 7, the
point of adjacency 36 (which consists of the two inner edges 34 of
the concavities 12) extends a greater distance away from the
leading edge 16 than does the exterior edges 32. In a further
exemplary embodiment, the area of adjacency protrudes at least 10
mm, for a blade up to 100 m span, further than the exterior edges
32. It should be appreciated that although the exterior edges 32
and area of adjacency 36 may be configured to protrude at any
desired distance from the leading edge 16 relative to each other,
the exemplary embodiment described above (i.e., wherein the
adjacency 36 protrudes further than the exterior edges 32) acts as
a tail or trailing edge extender to the blade 10, which (in use)
reduces drag via further separation of eddy currents.
[0026] Referring now to FIG. 8-10, the blade 10 the cavity is shown
as a depression 40. Like the concavity 12 of FIGS. 1-4, the
depression 40 is defined by the area 24, which is disposed along
the trailing edge 18. Again, similarly to the concavity 12, the
depression 40, is disposed along the trailing edge 18 in such a way
that it interrupts a seam line 26 or relative apex of the trailing
edge 18. The only substantial difference between the depression 40
and the concavity 12 is that the depression 40 achieves a depth
into the blade 10 via depression walls 42 that are not continuously
curved into contact with a deepest extent of the depression 40. In
other words, the depression 40 is defined by depression walls 42
that terminate at a depression surface 44 (i.e. the deepest extent)
at distinct, non-curved junction 48.
[0027] As is shown in FIGS. 8-10, the depression 40, like the
curvature 12, extends into the blade body 14 in a direction of the
leading edge 16. Referring to FIG. 9, the depression surface 44 may
be depressed into the body 14 such that the surface 44 includes a
width 46 relative to the depression 40. Referring to FIG. 10, the
depression surface 44 may also be depressed into the body 14 such
that the surface 44 includes a length 48 relative to the depression
40. Additionally, the depression 40 may include a consistent depth
from the trailing edge 18 across a length and width of the
depression 40.
[0028] Referring to FIGS. 11 and 12, the depression surface 44 may
also itself include a concavity 50, wherein said concavity 50
includes a curvature 52 that extends in the longitudinal direction
27 relative to the longitudinal extent 29 of the blade body 18,
and/or a curvature 54 that extends in a circumferential direction
30 relative to a circumferential area 31 of the blade body 14. In
addition, it should be appreciated that the depression wall may
include any concavity or convexity relative to a vector between a
relative outer extent of the walls 42 and the depression surface
44.
[0029] Referring now to FIGS. 13 and 14, the trailing edge cavity
12 may also be triangular in shape. That is the cavity may extend
into the body 14 of the blade 10 via a relatively upside down
triangle (upside down relative to the Figures). As is shown in FIG.
13, the triangle shape is defined by two sloping surfaces 60
sloping along the length 48 of the cavity 12. As is shown in FIG.
14, the triangle shape is defined by two sloping surfaces 60
sloping along the width 48 of the cavity 12.
[0030] It should be appreciated that the depression and triangular
embodiments of FIGS. 8-14 may be configured to include the depths,
and multiple disposals along the blade 10, that are discussed
relative to the concavity embodiments of FIGS. 1-6. In addition, it
should be appreciated that all of the embodiments of FIGS. 1-14 may
include concavities of cylindrical, spherical, elliptical or like
contours.
[0031] While the invention has been described in detail in
connection with only a limited number of embodiments, it should be
readily understood that the invention is not limited to such
disclosed embodiments. Rather, the invention can be modified to
incorporate any number of variations, alterations, substitutions or
equivalent arrangements not heretofore described, but which are
commensurate with the spirit and scope of the invention.
Additionally, while various embodiments of the invention have been
described, it is to be understood that aspects of the invention may
include only some of the described embodiments. Accordingly, the
invention is not to be seen as limited by the foregoing
description, but is only limited by the scope of the appended
claims.
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