U.S. patent application number 16/780151 was filed with the patent office on 2020-06-11 for fluid-redirecting structure.
The applicant listed for this patent is Ryan CHURCH. Invention is credited to Ryan CHURCH.
Application Number | 20200182220 16/780151 |
Document ID | / |
Family ID | 62062771 |
Filed Date | 2020-06-11 |
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United States Patent
Application |
20200182220 |
Kind Code |
A1 |
CHURCH; Ryan |
June 11, 2020 |
FLUID-REDIRECTING STRUCTURE
Abstract
A fluid-redirecting structure includes a rigid body having an
upstream end, a downstream end, and an axis of rotation, the rigid
body incorporating a plurality of troughs each spiralled from a tip
at the upstream end to the downstream end about the axis of
rotation, the troughs being splayed with respect to the axis of
rotation thereby to, proximate the downstream end, direct incident
fluid along the troughs away from the axis of rotation.
Inventors: |
CHURCH; Ryan; (Toronto,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CHURCH; Ryan |
Toronto |
|
CA |
|
|
Family ID: |
62062771 |
Appl. No.: |
16/780151 |
Filed: |
February 3, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15501475 |
Feb 3, 2017 |
10578076 |
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PCT/CA2015/050739 |
Aug 5, 2015 |
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16780151 |
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62033331 |
Aug 5, 2014 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F03D 1/0691 20130101;
F05B 2250/15 20130101; F05B 2260/30 20130101; F05B 2260/96
20130101; B64C 23/072 20170501; F03D 17/00 20160501; F05B 2250/611
20130101; Y02E 10/72 20130101; B63H 1/28 20130101; F05B 2250/183
20130101; B64C 11/14 20130101; F05B 2240/221 20130101; F03D 1/0625
20130101; Y02T 50/10 20130101; F05B 2240/30 20130101; B64C 11/18
20130101; F05B 2240/133 20130101; Y02E 10/721 20130101; F05B
2250/25 20130101; F05B 2250/16 20130101; Y02E 10/726 20130101; F03D
1/0633 20130101; F03D 1/0675 20130101; F03D 1/0608 20130101; F03D
1/0666 20130101; Y02T 50/164 20130101 |
International
Class: |
F03D 1/06 20060101
F03D001/06; F03D 17/00 20060101 F03D017/00; B64C 23/06 20060101
B64C023/06; B64C 11/18 20060101 B64C011/18; B63H 1/28 20060101
B63H001/28; B64C 11/14 20060101 B64C011/14 |
Claims
1. A fluid-redirecting structure attached to a turbine , the
fluid-redirecting structure comprising: an ultrasonic noise inducer
adapted for repelling one or more animals from the turbine by
generating ultrasonic sound waves.
2. The fluid-redirecting structure of claim 1, wherein the
ultrasonic noise inducer generates the ultrasonic soundwaves at a
frequency of 15 KHz or greater with a sound pressure at 1 meter of
approximately 95 to approximately 102 dB.
3. The fluid-redirecting structure of claim 1, wherein ultrasonic
noise inducer is positioned inside a nacelle or a nose cone of the
fluid-redirecting structure.
4. The fluid-redirecting structure of claim 1, wherein the
fluid-redirecting structure is attached to the turbine at a center
axis of the turbine; and the fluid-redirecting structure comprises
a plurality of troughs, such that each of these troughs in a
corresponding downstream section become aligned with an upwind
power-producing airfoil portion of a respective rotor blade of said
turbine, coming within close proximity thereof to the leading edge
of this blade, creating a gap between an outer most portion of a
downstream end of the fluid-redirecting device and the blade.
5. The fluid-redirecting structure of claim 4, wherein the
fluid-redirecting structure is a nosecone or a hub of a wind
turbine.
6. The fluid-redirecting structure of claim 4, wherein the
plurality of troughs are configured to direct incident wind
reaching the downstream end of the troughs outwards and along the
troughs in a direction substantially normal to the axis of rotation
and thereby along the front surface of a respective rotor blade of
the turbine.
7. The fluid-redirecting structure of claim 4, wherein the
plurality of troughs are spiraled with respect to the axis of
rotation, spiraled in an opposite direction of a rotational
direction of rotor blades of the turbine.
8. The fluid-redirecting structure of claim 4, wherein the
plurality of troughs originate from an upstream tip common to all
of the plurality of troughs.
9. The fluid-redirecting structure of claim 8, wherein each trough
of the plurality of troughs has a downstream portion coupled to the
corresponding rotor blade, each trough directing wind from the
upstream tip to the corresponding rotor blade.
10. The fluid-redirecting structure of claim 9, wherein each trough
of the plurality of troughs is wider in the downstream portion
relative to an upstream portion proximate to the upstream tip.
11. The fluid-redirecting structure of claim 9, wherein the
downstream portion of each trough of the plurality of troughs is
coupled to the corresponding rotor blade at a coupler having a
surface that is curved to prevent incident wind from escaping over
an edge of the trough.
12. The fluid-redirecting structure of claim 10, wherein the
coupler includes an arced wall that extends about 90 degrees in an
upstream direction.
13. The fluid-redirecting structure of claim 10, wherein the
coupler includes an arced wall that curves in a downstream
direction before arcing in an upstream direction.
14. The fluid-redirecting structure of claim 12, wherein the
coupler extends 90 degrees in the downstream direction before
arcing in the upstream direction.
15. The fluid-redirecting structure of claim 13, wherein the
coupler includes an arced wall that curves in a downstream
direction before arcing in an upstream direction.
16. The fluid-redirecting structure of claim 10, wherein the
coupler includes a plurality of retention structures each having an
arced elongate wall that is C-shaped in cross-section.
17. The fluid-redirecting structure of claim 16 wherein a portion
of a surface of each trough that faces the incident wind is
gradually bent to a maximum angle of approximately 270 degrees.
18. The fluid-redirecting structure of claim 4, wherein each trough
has a first stage extending between the upstream tip and a central
point of the trough, and a second stage extending between the
central point and the downstream portion of the trough, each trough
having different incident flow directing characteristics in the
first stage relative to the second stage.
19. A method for repelling one or more animals proximate to a
turbine, the method comprising: transmitting ultrasonic sound waves
towards one or more animals proximate to the turbine, the
ultrasonic soundwaves transmitted from a unit in the nose cone or
the nacelle unit, or any other area which does not affect the
aerodynamic properties of the horizontal-axis wind turbine at a
frequency of 15 KHz or greater.
20. A nosecone located at a center axis of a turbine, the nosecone
comprising: an ultrasonic sound inducer configured for transmitting
ultrasonic sound waves or repelling one or more animals proximate
to a turbine by generating ultrasonic sound waves, the ultrasonic
soundwaves transmitted at a frequency of 15 KHz or greater.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. application Ser.
No. 15/501475, filed on Aug. 5, 2015, entitled "FLUID-REDIRECTING
STRUCTURE", which is a 371 U.S. National Stage Application of
PCT/CA2015/050739 and claims all benefit, including priority under
35 U.S.C. 119(e) from U.S. Provisional Patent Application Ser. No.
62/033,331 filed on Aug. 5, 2014, the contents of which are
incorporated in their entirety by reference herein.
FIELD OF THE INVENTION
[0002] The present invention relates generally to turbines and
propellers, and more particularly to a fluid-redirecting structure
for a turbine or a propeller.
BACKGROUND OF THE INVENTION
[0003] Horizontal-axis wind turbines for generating electricity
from rotational motion are generally comprised of one or more rotor
blades each having an aerodynamic body extending outwards from a
horizontal shaft that is supported by, and rotates within, a wind
turbine nacelle. The rotor blades are examples of structures
adapted to traverse a fluid environment, where the environment is
primarily ambient air. The nacelle is supported on a tower which
extends from the ground or other surface. Wind incident on the
rotor blades applies pressure causing the rotor blades to move by
rotating the shaft from which they extend about the horizontal
rotational axis of the shaft. The shaft is, in turn, associated
with an electricity generator which, as is well-known, converts the
rotational motion of the shaft into electrical current for
transmission, storage and/or immediate use. Horizontal-axis wind
turbines are generally very well-known and understood, though
improvements in their operation to improve the efficiency of power
conversion and their overall operational characteristics are
desirable.
[0004] Incident wind at even low speeds can cause the rotor blades
to rotate very quickly. As would be well-understood, for a given
rotational velocity, the linear velocity of a rotor blade is lowest
in the region of its root--the portion of the rotor blade proximate
to the shaft. Similarly, the linear velocity of the rotor blade is
highest in the region of its wingtip--the portion of the rotor
blade distal from the shaft. Particularly at higher linear
velocities, aspects of the rotor blade can generate significant
aeroacoustic noise as the rotor blade rapidly "slices" through air
along its rotational path. This noise can be quite uncomfortable
for people and animals in the vicinity to witness. However, the
noise can also be an indicator that operation is not efficient, and
maximum wingtip speed can actually be limited by such
inefficiencies.
[0005] Horizontal-axis wind turbines are comprised of at least two
and typically three rotor blades. The total swept path of the rotor
blade(s) is considered to be the measure of the total kinetic
energy available to the wind turbine in that plane. Current wind
technologies are able to extract only a fraction of the kinetic
energy of the incident wind. The maximum theoretical value of
kinetic energy extraction from the wind--which is known as the Betz
Limit--was demonstrated in 1919 by Albert Betz according to a
principle known as Betz's Law. According to Betz's Law, the maximum
coefficient of performance (Cp) in wind kinetic energy extraction,
the Betz Limit, is 59.3%.
[0006] Current wind technologies have, in reality, a much lower Cp
than the Betz Limit. Efficiencies of wind turbines have been
increasing in recent years, mostly through advances in rotor blade
designs. However, some nascent research has begun to explore the
utilization of wind incident in the central hub portion in front of
the plane of rotor blade travel to improve efficiency and yield and
decrease noise emissions.
[0007] The portion in front of the central hub where the rotor
blade(s) are attached may or may not be covered by a nose cone. The
nose cone commonly acts as a protective shield for the hub of a
wind turbine. To date, nose cones are not generally configured to
aid in rotating the shaft of the wind turbine or to act in any way
to produce energy. To this end, it is a common understanding that
the total swept path of the rotor blade(s) is considered to be the
measure of the possible kinetic energy available to the wind
turbine in that plane and that the kinetic energy of the wind in
upstream of the wind turbine hub is currently under-utilized.
[0008] European Patent Application No. EP2592265 to Orbrecht et al.
discloses a power producing spinner for a wind turbine. This
application describes an area for airfoil extension over the root
area of the rotor blade(s), connecting at the hub region and an
upwind airfoil portion disposed upwind of an inboard portion of
each blade of the wind turbine; the wind turbine having a plurality
of blades interconnected about an axis of rotation by a hub. The
patent application further describes the ability of the power
producing spinner to increase the efficiency of the wind turbine by
increasing an axial induction to air flowing over the power
producing spinner and directing an air flow outboard to
aerodynamically useful regions of the blades.
[0009] U.S. Pat. No. 8,287,243 to Herr et al. discloses a spinner
of a wind turbine. The air-flow in an inner rotor section may pass
the rotor of the wind turbine without being used for energy
production. A cylindrical spinner deflects wind around the rotor
blade root(s) so that there is an increase in the efficiency of an
existing wind turbine.
[0010] The control of yaw of a wind turbine is important to
maintain maximal efficiencies, by containing wind incident to
roughly 90 degrees from the spinning of the rotor blades.
Currently, this is achieved via active systems that reside at the
base of the nacelle at the point of connection with the tower, as
in U.S. Pat. No. 7,944,070 to Rosenvard et al. and U.S. Pat. No.
8,899,920 to Anderson. These active systems are controlled by
sensors located on the exterior of the nacelle at the rear portion
from first wind incident. Thus, these sensors are informed of wind
conditions, most importantly speed and direction, after the wind
has passed by the rotor blades. As such, there is a delay in the
information of wind speed and direction to the active yaw system at
the base of the nacelle.
[0011] European Patent Application Publication No. EP 2048507 to
LeClair et al. discloses sensors located on the front of a
nosecone. However, the sensors send their information to an active
systems of motors and gears that are not able to actively move the
turbine such that maximal efficiencies are generated without a
feedback loop and subsequent delay. Furthermore, these systems
similarly require electrical power to operate.
[0012] Traditional nose cones are attached to the hub through a
spinner. The spinner may then be attached to the hub through
several methods including struts and having its form wrap around
the root(s) of the rotor blade(s) to secure it in place. Most of
these methods require the blades to not be present for spinner
attachment, which may be fine for assembling a new wind turbine but
can be time consuming and costly for retrofitting an operating
turbine.
It is well known that the hubs and nacelles of a wind turbine
require ventilation due to the heat that is created within them.
Many techniques are known to ventilate the air within these
structures.
[0013] Surface textures have also been known to improve the laminar
flow over objects. These textures are often self-similar and
repeating in nature. These may be recessed into the form, or
project out of the form, and/or may also be U-shaped or V-shaped
troughs that swerve or zig-zag in beneficial ways, or vortex
generators that extend out of the form.
SUMMARY OF THE INVENTION
[0014] In accordance with an aspect, there is provided a
fluid-redirecting structure comprising a rigid body having an
upstream end, a downstream end, and an axis of rotation, the rigid
body incorporating a plurality of troughs each spiralled from a tip
at the upstream end to the downstream end about the axis of
rotation, the troughs being splayed with respect to the axis of
rotation thereby to, proximate the downstream end, direct incident
fluid along the troughs away from the axis of rotation.
[0015] The fluid-redirecting structure described herein may either
be fully integrated with, or fitted and attached to, a hub
structure of a turbine such as a horizontal-axis wind turbine, in
the central position thereby to replace an existing nose cone.
[0016] The fluid-redirecting structure, when associated with a wind
turbine, faces incident wind flowing from an upstream location
towards a downstream location, receives the wind, and rotates in
response to the flow of the incident wind in unison with rotor
blades of the wind turbine as the incident wind pushes against and
through the troughs in its path from the upstream end through to
the downstream end. Furthermore, the fluid-redirecting structure
directs the incident wind reaching the downstream end of the
troughs outwards and along the troughs in a direction substantially
normal to the axis of rotation and thereby along the front surface
of a respective rotor blade of the wind turbine.
[0017] The trough portion at the downstream end of the
fluid-redirecting structure is generally aligned with an upwind
power producing rotor blade portion, and in embodiments like the
rotor blade may assume the shape of an airfoil and/or may form a
new leading edge section of the rotor blade(s) and/or may form a
new trailing edge section of the rotor blade(s).
[0018] The fluid-redirecting structure thereby acts to harness
incident wind that is still upstream of the rotor blades of the
wind turbine to rotate the spinner, thereby to increase the
efficiency and/or decreases the noise emissions of the wind turbine
as a whole through its application and use and by increasing the
time over which energy extraction occurs.
[0019] Further, the direction and re-distribution of the kinetic
energy of incident wind away from the axis of rotation of the
turbine but against the rotor blades provides a source of kinetic
energy that heretofor has been lost from the hub area, in a quiet
manner.
[0020] In accordance with another aspect, there is provided a
fluid-redirecting structure for a turbine comprising a rigid body
attachable to a hub structure of the turbine and incorporating a
plurality of spiral troughs each for receiving and directing wind
incident on the rigid body against a front surface of a
corresponding turbine blade.
[0021] In an embodiment, the fluid-redirecting structure can be
retrofitted to existing turbines either in lieu of, or in
conjunction with, a standard paraboloidal nose cone thereby to
provide efficiency and power-generating benefits to the existing
turbine.
[0022] The direction in which the troughs are spiralled with
respect to the axis of rotation is chosen to correspond with the
opposite direction of the rotational direction of the drive shaft
and rotor blades. As such, a counterclockwise direction of intended
rotation for the rotor blade(s) would coordinate with a clockwise
spiral for the troughs of the fluid-redirecting device around the
axis of rotation, whereas a clockwise direction of intended
rotation for the rotor blade(s) would coordinate with a
counterclockwise spiral for the troughs of the fluid-redirecting
device around the axis of rotation.
[0023] The present patent application includes description of
opportunities for improving on the traditional aspects of a nose
cone for a wind or water turbine, as well as for a propeller for an
aircraft, watercraft or spacecraft. The uniquely
biologically-inspired configurations can conveniently be
retrofitted onto the hub structure in front of the plane of
movement of the rotor blade(s), and is self-orienting. The
fluid-redirecting structures described herein aim to produce
rotational motion in the drive shaft of a turbine using incident
fluid, such as wind, that is in front of the plane of rotor blade
travel as well as to direct such incident fluid that is in front of
the hub structure to and over the power producing regions of the
rotor blade(s), thus increasing the overall efficiency of the
turbine by using the under-utilized energy available in the fluid
around the hub area.
[0024] Through this invention, the wind turbine of the prior art
will see an increase in efficiency from the wind turbine with the
current invention integrated, if installed upwind from the prior
art. The same increase in efficiency may also be seen if one wind
turbine with the current invention integrated is installed upwind
of another wind turbine with the current invention integrated.
[0025] In accordance with another aspect, there is provided a
fluid-redirecting structure for a turbine comprising a rigid body
attachable to at least one of a hub structure and rotor blades of
the turbine and incorporating a plurality of spiral troughs each
for receiving and directing fluid incident on the rigid body
against a front surface of a corresponding turbine blade.
In accordance with another aspect, there is provided a
fluid-redirecting structure for a propeller comprising a rigid body
attachable to at least one of a hub structure and propeller blades
of the propeller and incorporating a plurality of spiral troughs
each for receiving and directing fluid incident on the rigid body
against a front surface of a corresponding propeller blade and/or
rotor blade.
[0026] Other aspects as well as advantages will be described
herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Embodiments of the invention will now be described with
reference to the appended drawings in which:
[0028] FIG. 1 is a side elevation view of a horizontal axis wind
turbine, according to the prior art;
[0029] FIG. 2A is a side elevation view of a horizontal axis wind
turbine incorporating a fluid-redirecting structure in accordance
with an embodiment of the invention;
[0030] FIG. 2B is a front perspective view of the horizontal axis
wind turbine of FIG. 2A;
[0031] FIG. 3A is a side elevation view of a fluid-redirecting
structure according to an embodiment of the invention;
[0032] FIG. 3B is a front elevation view of the fluid-redirecting
structure of FIG. 3A;
[0033] FIGS. 4A and 4B are cross-sectional views of the
fluid-redirecting structure of FIG. 3A, from a position proximate
the upstream end (4A) and from a position closer to the down-stream
end (4B);
[0034] FIGS. 5A, 5B, 5C and 5D are cross-sectional views of various
alternative embodiments of retention structures at edges of
troughs;
[0035] FIG. 6 is a front perspective view of an attachment
structure for the fluid-redirecting structure of FIG. 3A
interfacing with a hub structure of a wind turbine;
[0036] FIG. 7 is a rear perspective view of an alternative
attachment structure;
[0037] FIG. 8 is a rear perspective view of another alternative
attachment structure;
[0038] FIG. 9 is a side elevation view of the fluid-redirecting
structure of FIG. 8, further showing an attachment system and the
relationship between the fluid-redirecting structure and a spinner,
hub structure, and rotor blades of a turbine;
[0039] FIG. 10 is a front elevation view of a fluid-redirecting
structure having surface texture according to an embodiment;
[0040] FIG. 11 is a front elevation view of a fluid-redirecting
structure according to an embodiment having trough ends that
terminate flush with respective rotor blades;
[0041] FIG. 12 is a side elevation view of an alternative
fluid-redirecting structure according to an alternative embodiment
of the invention;
[0042] FIG. 13 is a side elevation view of the fluid-redirecting
structure of FIG. 12, further showing ventilation structure and the
relationship between the fluid-redirecting structure and a spinner
and hub structure of a turbine;
[0043] FIG. 14 is a front perspective view of a fluid-redirecting
structure having troughs that are aerodynamic in cross-section,
according to an embodiment; and
[0044] FIG. 15 is a front elevation view of an urban wind turbine
incorporating a fluid-redirecting structure.
DETAILED DESCRIPTION
[0045] Reference will now be made in detail to the various
embodiments of the invention, one or more examples of which are
illustrated in the figures. Each example is provided by way of
explanation of the invention, and is not meant as a limitation of
the invention. For example, features illustrated or described as
part of one embodiment can be used on or in conjunction with other
embodiments to yield yet a further embodiment. It is intended that
the present invention includes such modifications and
variations.
[0046] FIG. 1 is a side elevation view of a horizontal axis wind
turbine 10, according to the prior art. Wind turbine 10 includes a
tower 100 supported by and extending from a surface S, such as a
ground surface. Supported by tower 100, in turn, is a nacelle 200
extending horizontally. A hub structure with a spinner 300 is
rotatably mounted at a front end of nacelle 200 and is rotatable
with respect to nacelle 200 about a rotation axis R. Spinner 300
receives and supports multiple rotor blades 400 that each extend
outwardly from spinner 300. Rotor blades 400 catch incident wind
W.sub.i flowing towards the wind turbine 10 and are caused to
rotate. Due to their being supported by spinner 300, rotor blades
400 when rotating cause spinner 300 to rotate about rotation axis R
thereby to cause rotational motion that can be converted in a
well-known manner into usable electrical or mechanical power. In
this sense, rotor blades 400 are each structures adapted to
traverse a fluid environment, where the fluid in this embodiment is
ambient air. Nacelle 200 may be rotatably mounted to tower 100 such
that nacelle 200 can rotate about a substantially vertical axis
(not shown) with respect to tower 100, thereby to enable rotor
blades 400 to adaptively face the direction from which incident
wind W.sub.i is approaching wind turbine 10. A nose cone 500 of
generally a uniform paraboloidal shape is shown mounted to a front
end of spinner 300 to deflect incident wind W.sub.i away from
spinner 300.
[0047] FIG. 2A is a side elevation view of a horizontal axis wind
turbine 15 incorporating a fluid-redirecting structure 600 in
accordance with an embodiment of the invention, and FIG. 2B is a
front perspective view of horizontal axis wind turbine 15.
[0048] Wind turbine 15 includes a tower 100 supported by and
extending from a surface S, such as a ground surface. Supported by
tower 100, in turn, is a nacelle 200 extending horizontally. A hub
structure with a spinner 300 is rotatably mounted at a front end of
nacelle 200 and is rotatable with respect to nacelle 200 about a
rotation axis R. Spinner 300 receives and supports multiple rotor
blades 400 that each extend outwardly from spinner 300. Rotor
blades 400 catch incident wind W.sub.i flowing towards the wind
turbine 15 and are caused to rotate. Due to their being supported
by spinner 300, rotor blades 400 when rotating cause spinner 300 to
rotate about rotation axis R thereby to cause rotational motion
that can be converted in a well-known manner into usable electrical
or mechanical power. Nacelle 200 may be rotatably mounted to tower
100 such that nacelle 200 can rotate about a substantially vertical
axis (yaw axis, not shown) with respect to tower 100, thereby to
enable rotor blades 400 to adaptively face the direction from which
incident wind W.sub.i is approaching wind turbine 15.
[0049] In this embodiment, fluid-redirecting structure 600 is shown
mounted to a front end of spinner 300 and is rotatable, along with
spinner 300 and rotor blades 400, about rotational axis R.
[0050] FIG. 3A is a side elevation view of fluid-redirecting
structure 600, enlarged for ease of explanation, and FIG. 3B is a
front elevation view of fluid-redirecting structure 600.
Fluid-redirecting structure 600 includes a rigid body 602 having an
upstream end 602U and a downstream end 602D. The rigid body 602
incorporates a plurality of troughs, in this embodiment three (3)
troughs 604A, 604B and 604C. Each trough 604A, 604B and 604C is
spiralled from a tip 606 at upstream end 602U to the downstream end
602D about rotational axis R. The troughs 604A, 604B and 604C are
also each splayed with respect to the rotational axis R thereby to,
proximate the downstream end 602D, direct incident fluid--in this
embodiment incident wind W.sub.i--along the troughs 604A, 604B and
604C in a direction substantially normal to the axis of rotation
R.
[0051] In this embodiment, the troughs 604A, 604B and 604C at the
upstream end 602U generally come from a point proximate to tip 606
along a direction generally parallel to the rotational axis R and
then, as they progress in spiral towards the downstream end 602D
splay outwards progressively away from the rotational axis thereby
to re-direct incident wind W.sub.i (shown going into the page in
FIG. 3B) so that the re-directed wind W.sub.RD flows along the
front surface of rotor blades 400.
[0052] As shown particularly in FIG. 3B, each of troughs 604A, 604B
and 604C is generally a single-stage format i.e., is progressively
gradually increased in focal radius of the spiral from the upstream
end 602U to the downstream end 602D. Furthermore, there is a
corresponding gradual increase in the width of the trough from
upstream end 602U to downstream end 602D. In this embodiment, each
of troughs 604A, 604B and 604C is widened generally parabolically,
such that there is a gradual increase in the width of the trough
from upstream end 602U to downstream end 602D. In alternative
embodiments, the troughs may be contoured so as to, when going from
upstream end 602U to downstream end 602D, gradually increase in
width, then maintain a steady width through an intermediate region
such that the edges of the trough run parallel, then gradually
increase in width again to the downstream end 602D. In yet another
alternative embodiment, the troughs may be contoured so as to, when
going from upstream end 602U to downstream end 602D, gradually
increase in width, then maintain a steady width through a
downstream region until the downstream end 602D without increasing
again in width.
[0053] FIGS. 4A and 4B are cross-sectional views of
fluid-redirecting structure 600, from a position A proximate the
upstream end (shown from A in FIG. 3A) and from a position closer
to the downstream end (shown from B in FIG. 3A), showing the
different focal radii FR_A and FR_B of the troughs 604A, 604B and
604C, as well as the different widths of the troughs 604A, 604B and
604C. It will be noted that, in this embodiment, the width of each
trough 604A, 604B and 604C progresses proportionally with the focal
radius.
[0054] As shown in FIGS. 3A, 3B, 4A and 4B, each trough 604A, 604B
and 604C has opposite edges extending from the upstream end 602U to
the downstream end 602D. In this embodiment, one of the edges of
each trough 604A, 604B and 604C incorporates respective retention
structure 605A, 605B and 605C for inhibiting incident fluid--in
this embodiment incident wind--from exiting a respective trough
604A, 604B and 604C and for directing the incident fluid along the
trough.
[0055] In this embodiment, each retention structure 605A, 605B and
605C is an arced elongate wall that is generally a C-shape in cross
section. In particular, a portion of surface of each trough 604A,
604B and 604C that faces incident wind Wi along the edge is
gradually bent on itself to a maximum angle of two hundred and
seventy (270) degrees. The cross-section of the troughs 127 may
further be of any beneficial elliptical or bowed shape.
[0056] FIGS. 5A, 5B, 5C and 5D are cross-sectional views of various
alternative embodiments of retention structures for a trough such
as trough 604B, along a portion of its edge. For example, FIG. 5A
is a view of a retention structure 607B that is a very-slightly
arced wall the extends generally 90 degrees in an upstream
direction, FIG. 5B is a view of a retention structure 609B that is
a slightly arced wall with a wider radius than that of FIG. 5A and
that dips slightly in a downstream direction prior to arcing in an
upstream direction, FIG. 5C is a view of retention structure 605B
of fluid-redirecting structure 600 as shown in FIG. 4B that extends
generally 90 degrees in an upstream direction before curving, and
FIG. 5D is a view of a retention structure 611B that is similar to
retention structure 605B but that, like retention structure 605B,
dips slightly in a downstream direction prior to arcing upstream
again. In still further embodiments, the retention structure may be
extended in its generally C-shape so as to be generally U-shaped in
cross-section.
[0057] The retention structures inhibit incident wind Wi from
spilling over the edge of the troughs thereby to keeps more wind
within the troughs in the regions at which the retention structures
extend from the edges.
[0058] FIG. 6 is a front perspective view of an attachment
structure, in the form of a nose clamp assembly 650, for
interfacing the fluid-redirecting structure 600 with a hub
structure of a horizontal-axis wind turbine, such as wind turbine
15. Nose clamp assembly 650 is configured such that the existing
hub structure 300 and rotor blades 400 do not need to be
disassembled in order to retrofit wind turbine 15 with
fluid-redirecting structure 600 using nose clamp assembly 650. As
shown, nose clamp assembly 650 is attached onto the existing hub
structure 300 of the wind turbine 15 and is further stabilized to
the roots 402 of the rotor blade 400 through support devices of
nose clamp assembly 650 including brackets 656, clamps 652, and
rollers and/or castors 654. Alternatively, one or more clamps, one
or more braces, one or more brackets, one or more struts, one or
more castors, and one or more rollers, or combinations thereof may
be employed as attachment mechanisms.
[0059] It will be noted that preferably the rollers and/or castors
654 are interfaced with the fluid-redirecting structure 600 and the
turbine 15 to enable nose clamp assembly 650 to accommodate
selective adjustments to the pitch of each rotor blade 400 with
respect to the hub structure. In this case, the rollers roll along
the outer surface of the root 402 of a respective rotor blade 400,
while retaining fluid-redirecting structure 600 in a central
position with respect to the hub structure.
[0060] FIG. 7 is a rear perspective view of an alternative
attachment structure, in the form of a nose clamp assembly 660, for
attaching the fluid-redirecting structure 600 to only the roots 402
of rotor blades 400 of horizontal-axis wind turbine 15. In this
embodiment, the existing spinner 300 and rotor blades 500 do not
have to be removed prior to wind turbine 15 being retrofitted with
fluid-redirecting structure 600. As shown, nose clamp assembly 660
is stabilized to the roots 402 of the rotor blade 400 through
support devices of nose clamp assembly 660 including brackets 656,
clamps 652, and rollers and/or castors 654. Alternatively, one or
more clamps, one or more braces, one or more brackets, one or more
struts, one or more castors, and one or more rollers, or
combinations thereof may be employed as attachment mechanisms.
[0061] It will be noted that preferably the rollers and/or castors
654 are interfaced with the fluid-redirecting structure 600 and the
turbine 15 to enable nose clamp assembly 660 to accommodate
selective adjustments to the pitch of each rotor blade 400 with
respect to the hub structure. In this case, the rollers roll along
the outer surface of the root 402 of a respective rotor blade 400,
while retaining fluid-redirecting structure 600 in a central
position with respect to the hub structure and the tip 606 in line
with the axis of rotation R.
[0062] In an alternative embodiment, the attachment system may be
configured to interface only with the hub structure of a wind
turbine, and thereby not physically contact its rotor blades.
[0063] FIG. 8 is a rear perspective view of an alternative
fluid-redirecting structure 700. Fluid-redirecting structure 700 is
similar to fluid-redirecting structure 600, in that
fluid-redirecting structure 700 includes a rigid body 702 having an
upstream end 702U and a downstream end 702D. The rigid body 702
incorporates a plurality of troughs, in this embodiment three (3)
troughs 704A, 704B and 704C. Each trough 704A, 704B and 704C is
spiralled from a tip 706 at upstream end 702U to the downstream end
702D about rotational axis R. The troughs 704A, 704B and 704C are
also each splayed with respect to the rotational axis R thereby to,
proximate the downstream end 702D, direct incident fluid--in this
embodiment incident wind W.sub.i--along the troughs 704A, 704B and
704C in a direction substantially normal to the axis of rotation
R.
[0064] In this embodiment, fluid-redirecting structure 700 includes
integral circular loops 740A, 740B and 740C affixed to the
rear-facing side of fluid-redirecting structure 700 and each
dimensioned to receive and seat a respective root 402 of a rotor
blade 400 (not shown in FIG. 8) prior to the roots 402 interfacing
with a hub structure of a turbine such as wind turbine 15. The
integral circular loops 740A, 740B and 740C are shown without any
rollers simply for clarity.
[0065] FIG. 9 is a side elevation view of fluid-redirecting
structure 700, further showing the hub structure 670 and its
relationship between the fluid-redirecting structure 700 and a
spinner 300 of the hub structure, and rotor blades 400 of a wind
turbine 15. Hub structure and integral circulate loops 740A, 740B
and 740C may be used to "bolt" fluid-redirecting structure 700 onto
the hub structure of the wind turbine 15 thereby to retrofit wind
turbine 15 with a fluid-redirecting structure, and interfaces with
struts 675 that may have been part of an original nose cone 500
and/or spinner 300.
[0066] FIG. 10 is a front elevation view of a fluid-redirecting
structure 800 having surface texture 855 on one of the troughs 804B
and showing an intended orientation of clockwise spin. The other
troughs 804A and 804C may have similar surface texture 855.
Fluid-directing structure 800 may be configured very similarly to
fluid-directing structures 600 and 700 and, in this embodiment, is
shown terminating at the downstream end such that its troughs 804A,
804B and 804C are integrated with respective rotor blades 400
thereby to provide a continuous front surface for receiving and
redirecting incident wind Wi in the directions shown by W.sub.RD.
The continuous front surface reduces interruptions in fluid flow
that could otherwise contribute to undesirable fluid drag.
[0067] The texture 855 may be of any configuration that reduces
fluid drag and therefore permits increased power production of the
fluid-redirecting structure 800. For example, texture may include
dimples. A close-up view of texture 855 can be seen at 860 which
shows dimples 861 that sink beneath the surface of the trough and
dimples 862 that rise above the surface. The side elevation
enlarged sub figure of FIG. 10 shown at 863 illustrates the
excavations of dimples 861 and their rise above the surface
862.
[0068] In an embodiment, there may also be included vortex
generators on the surface of the nose cone assembly. The
application of the surface texture may be done by any means during
manufacture or after installation.
[0069] FIG. 11 is a front elevation view of fluid-redirecting
structure 800 with the surface texture 855 not shown and showing an
intended orientation of counter-clockwise spin.
[0070] It will be appreciated that the direction in which the
troughs 804A, 804B and 804C are spiralled with respect to the axis
of rotation R corresponds with the opposite direction in which the
rotor blades 400 are intended to turn. As such, a counterclockwise
direction of intended rotation for the rotor blade(s) would
coordinate with a clockwise spiral for the troughs 804A, 804B and
804C about the axis of rotation R (into the page as shown in FIG.
11), whereas a clockwise direction of intended rotation for the
rotor blade(s) would coordinate with a counterclockwise spiral for
the 804A, 804B and 804C about the axis of rotation as in FIG. 10.
In this embodiment, the troughs 804A, 804B and 804C of
fluid-redirecting structure 800, where they respectively become
aligned with an upwind power-producing airfoil portion of a
respective rotor blade 400, may take on the cross-sectional shape
of an airfoil. Alternatively or in some combination the troughs
804A, 804B and 804C may form a new leading edge section of the
rotor blades 400 and/or may form a new trailing edge section of the
rotor blades 400.
[0071] FIG. 12 is a side elevation view of an alternative
fluid-redirecting structure 900. In this embodiment,
fluid-redirecting structure 900 has troughs 904A, 904B and 904C
that each have a first stage S1 progressively widened from the tip
906 at its upstream end 902U to a midpoint position P that is
intermediate the upstream end 902U and the downstream end 902D.
Each of troughs 904A, 904B and 904C also includes a second stage S2
progressively widened from the midpoint position P to the
downstream end 902D. Each trough 904A, 904B and 904C in its second
stage S1 is generally wider than in its first stage S2.
[0072] Each of stages S1 and S2 generally progressively widens
parabolically in shape. In this embodiment, midpoint position P is
halfway between the upstream and downstream ends. However, in
alternative embodiments the midpoint position P may be more that
halfway between the upstream and downstream ends, such as at the
three-quarters (3/4) position. Furthermore, troughs 904A, 904B and
904C may spiral around the rotational axis R between about one
hundred and eighty (180) degrees and about three hundred and sixty
(360) degrees. The contour of the spiral may go through many
deviations. For example, the spiral of a trough may begin at the
front tip 906 of the nose cone and continue through to the
downstream end 902D where its surface connects flush and/or comes
into close proximity with the upwind power producing airfoil
portion of a corresponding rotor blade 400. In embodiments, the
spiral may traverse any paraboloidal shape or multitudes thereof so
as to have more than two stages. After beginning at the tip 906, a
parabolic contour may then taper at a position near the midpoint
position P to reach a near-parallel line with the rotational axis
R. At this position near the midpoint position P, a parabolic
contour may then splay to a wider focal, of which half, or ninety
(90) degrees of its turn is completed. The contour may then taper
again near the hub structure to be parallel with the line of the
drive shaft, at which point a full one hundred and eighty (180)
degrees of the turn will be completed. This configuration thus
allows incident wind Wi to proceed in a step-wise fashion over the
multiple stages S1, S2 along the surface of a respective trough
904A, 904B, 904C, as inspired by the beak and head of a kingfisher,
and be directed onto the upwind power producing airfoil portion of
the corresponding rotor blade 400.
[0073] FIG. 13 is a side elevation view of fluid-redirecting
structure 900, further showing ventilation structure and the
relationship between the fluid-redirecting structure and a spinner
and hub structure 120 of a turbine. The ventilation structure
includes ventilation inlets 985, flexible tubes and/or hoses 986,
along with the relative inner positions of the existing hub
structure 120 and nosecone 500. In this embodiment, the
fluid-redirecting structure 900 may include ventilation inlets 985
on its surface within the second stage S2 to allow air to penetrate
into the nosecone 500 and hub structure 120 and/or nacelle 200 via
flexible tubes and/or hoses 986.
[0074] According to an aspect of another embodiment, the
fluid-redirection structure 900 may be a monocoque assembly with a
structural skin, and that is configured to enable an existing hub
structure 120 with spinner 300 and/or nosecone 500 to be received
at the downstream end 902D within the fluid-redirecting structure
900. In this embodiment, the fluid-redirecting structure is a
one-piece unit. In alternative embodiments, the fluid-redirecting
structure may be a multi-piece unit.
[0075] FIG. 14 is a front perspective view of a fluid-redirecting
structure 1000 having troughs 1004A, 1004B and 1004C that are
aerodynamic in cross-section, along with added aerodynamic airfoil
sections 1046.
[0076] According to this aspect, this may be achieved by having a
gap 1043 between the outermost portion of the downstream end 1002D
of the fluid-redirecting structure 1000 and an upwind power
producing airfoil portion of the wind turbine rotor blade(s) 400.
This method covers the root(s) region of the rotor blade(s) 402,
but allows for the flexibility of the material and/or the ability
to convert the outermost portion of the downstream end 1002D of the
fluid-redirecting structure 1000 into an airfoil section. This
effectively extends the length of the rotor blade(s) 400, creating
new leading 404 and trailing 405 edges. Furthermore, another
aerodynamic airfoil section 1046 may be added in a position
parallel to the rotor blade(s) 400, and slightly above the
outermost portion of the downstream end 1002D of the
fluid-redirecting structure 1000. This has the effect of preventing
any remaining kinetic energy in the wind incident Wi from exiting
the outermost portion of the downstream end 1002D of the
fluid-redirecting structure 1000 between the root(s) of the rotor
blade(s) 402 without first doing work on the fluid-redirecting
structure 1000 before hand. The work is shown here at Wii, where
the wind incident is made to divert its path along an aerodynamic
airfoil section 1046, thus doing work on that section and reducing
its kinetic energy, exiting out at We. This aerodynamic airfoil
section 1046 is attached to the rear portion of the troughs at
1005A and a front portion 1005B of the outermost portion of the
downstream end 1002D of the fluid-redirecting structure 1000
through any suitable method, such that a rotational force is
generated when wind incident Wi passes over it. According to
another aspect, this section 1046--along with any other section of
the fluid-redirecting structure 1000--may form a combination of two
(2) or more detachable sections.
[0077] Theoretical Considerations:
[0078] As stated above, the Betz limit is the maximum coefficient
of performance (Cp) in wind kinetic energy extraction, and is
59.3%. Known wind technologies have in reality a much lower Cp than
the Betz limit. The Betz law assumes that:
[0079] 1. The rotor does not possess a hub, this is an ideal rotor,
with an infinite number of blades which have no drag. Any resulting
drag would only lower this idealized value.
[0080] 2. The flow into and out of the rotor is axial. This is a
control volume analysis, and to construct a solution the control
volume must contain all flow going in and out, failure to account
for that flow would violate the conservation equations.
[0081] 3. The flow is incompressible. Density remains constant, and
there is no heat transfer.
[0082] 4. Uniform thrust over the disc or rotor area.
[0083] Assuming that there is an ideal wind turbine able to extract
the kinetic energy in the wind (E.sub.W) at an efficiency of 59.3%,
according to Betz limit, that the above ideal turbine has a frontal
surface area of SA.sub.f 19.6 m.sup.2 and that the wind speed is
2.78 m/s and the exterior temperature is 15.sup..quadrature., the
energy extracted by such an ideal wind turbine is as shown in
Equation 1 below, where Pw is the cubic power of the wind speed,
and Da is the air density, which equals 1.225 @ 15 degrees C.:
[0084] In terms of power production, over 1 hour of functioning in
these conditions the turbine will produce:
P.sub.(kinetic)=0.3879835 kWh
[0085] Small scale tests were conducted to determine the power
output of various wind turbine configurations at varying wind
speeds. These tests accurately reflected the size, shape, weight,
proportion, blade speed--wind speed ratio of current large scale
wind turbines.
[0086] As a baseline, let us assume a standard horizontal-axis wind
turbine is tested on this scale. Let us also assume the same
conditions, with a frontal surface area of 19.6 m.sup.2, a wind
speed of 2.78 m/s and the exterior temperature of
15.sup..quadrature.. When experiments were conducted and averaged,
the energy extracted by such a wind turbine was found to be:
[0087] E=358.25 Watts=0.35825 kW
[0088] As such, in terms of power production, over 1 hour of
functioning in these conditions the turbine would produce
P.sub.(kinetic)=0.35825 kWh.
[0089] This equates to a measure of 49.25% of the Betz limit, which
is about average for most large-scale horizontal-axis wind
turbines.
[0090] Now let us take a standard horizontal-axis wind turbine and
integrate the current invention, a nose cone assembly that is able
to extract a portion of the underutilize kinetic energy around the
hub region. Let us also take the same conditions, with a frontal
surface area of 19.6 m.sup.2, a wind speed of 2.78 m/s and the
exterior temperature of 15.sup..quadrature.. When experiments were
conducted, the energy extracted by such a wind turbine was found to
be E=439.30 Watts=0.43930 kW
[0091] In terms of power production, over 1 hour of functioning in
these conditions the turbine will produce: P.sub.(kinetic)=0.43930
kWh
[0092] This equates to a measure of 66.23% of the Betz limit, which
is +6.93% over the Betz limit. Below is a graph giving the
percentage of energy captured by the wind turbine without and with
the invention described herein against varying wind speeds. The
wind speeds in the conducted experiments were set in km/h, and then
later converted to m/s for the Betz equation, and shown in Table 1
below.
Table 1
[0093] Wind turbine nose cone assembly configurations described
herein are expected to improve the operational efficiency of wind
turbines by harnessing more of the available kinetic energy in
front of the plane of the rotor blade(s), especially around the hub
region and/or increase the available kinetic energy of the wind to
the rotor blade(s) and/or ventilate the hub and surrounding area
and/or reduce the operational noise emissions of the nose cone
and/or provide a quick attachment method for the nose cone assembly
and/or reduce wind turbine operational costs.
[0094] The above-described configurations to the nose cone of a
horizontal-axis wind turbine can also be applied to vertical-axis
wind turbines, and both of any scale. Such improvements may apply
equally well, mutatis mutandis, with such mutations as being
relevant, including but not limited to, high altitude wind power
(HAWP) devices, kite wind turbines, energy kites, tidal turbines,
urban wind turbines, propellers for airplanes, boats, gliders and
drones, jet engine caps, the bulbous bow of ships, and other
things. The invention or inventions described herein may be applied
to wind turbines having fewer or more blades than described by way
of example in order to increase the operational efficiency of a
wind turbine, to decrease maintenance costs and mechanical wear,
and to increase the scalability and marketability of such wind
turbines.
[0095] Some embodiments may have been described with reference to
method type claims whereas other embodiments may have been
described with reference to apparatus type claims. However, a
person skilled in the art will gather from the above and the
following description that, unless otherwise notified, in addition
to any combination of features belonging to one type of subject
matter also any combination between features relating to different
subject matters, in particular between features of the method type
claims and features of the apparatus type claims is considered as
to be disclosed with this document.
[0096] The aspects defined above and further aspects are apparent
from the examples of embodiment to be described hereinafter and are
explained with reference to the examples of embodiment.
[0097] Other aspects may become apparent to the skilled reader upon
review of the following.
[0098] Although embodiments have been described with reference to
the drawings, those of skill in the art will appreciate that
variations and modifications may be made without departing from the
spirit and scope thereof as defined by the appended claims.
[0099] It should be noted that the term `comprising` does not
exclude other elements or steps and the use of articles "a" or "an"
does not exclude a plurality. Also, elements described in
association with different embodiments may be combined. It should
be noted that reference signs in the claims should not be construed
as limiting the scope of the claims.
[0100] Although embodiments have been described with reference to
the drawings, those of skill in the art will appreciate that
variations and modifications may be made without departing from the
spirit, scope and purpose of the invention as defined by the
appended claims.
[0101] For example, alternative construction of fluid-redirecting
devices could employ a "spaceframe" design with metal latticework
wrapped in a polyester weave coat. Alternatively, the design could
employ a voronoi pattern.
[0102] While the description above has been primarily with regard
to fluid-redirecting structures for horizontal-axis wind turbines,
the structures described may be applicable to other devices, such
as wind turbines, tidal turbines, hydroelectric dam turbines, kite
turbines, high altitude wind power (HAWP) devices, kite wind
turbines, energy kites and urban wind turbines. All of these
devices could be improved with a fluid-redirecting device such as
described herein, within the need for attached rotor blades. For
example, the nosecone can be placed within a circular structure to
rotate. In particular, FIG. 15 is a front elevation view of an
urban wind turbine incorporating a fluid-redirecting structure in
such a manner.
[0103] All of the devices mentioned use the same device with
variations in size.
[0104] Propellers for aircraft (such as a glider, civilian
airplane, drone or jet engine caps), watercraft, spacecraft,
turbochargers and the like could employ the above-described
fluid-redirecting structure, except that power would be used in the
spinning of this device, and thus it would be spun the opposite
direction, to induce flow of the fluid towards the back of the
structure. The spiraling would have a direction beneficial to such
a configuration.
[0105] In accordance with another aspect, an ultrasonic noise
inducer for the purpose of repelling any animal of flight from a
horizontal or a vertical-axis wind turbine may be integrated with a
fluid-redirecting structure such as is described herein, or into a
standard paraboloidal nose cone or other structure. To the
knowledge of the present inventor, no satisfactory solution exists
to discourage or prevent flying animals of any sort from coming
into contact with rotor blades or any other part of a wind turbine,
that uses ultrasonic sound waves, so as to reduce or prevent animal
death and damage to the wind turbine.
[0106] According to a first aspect, an ultrasonic noise inducer of
15 KHz or greater with a sound pressure at 1 meter of 95-102 dB is
fitted inside the nose cone or the nacelle unit, or any other area
which does not affect the aerodynamic properties of the
horizontal-axis wind turbine for the purpose of repelling animals
of flight from striking a horizontal-axis or vertical-axis wind
turbine, wherein the ultrasonic noise inducer is placed in any
vicinity around or in the wind turbine such that the desired effect
of repelling the animals of flight can be achieved and the
aerodynamic properties of the wind turbine are not affected,
wherein the installation of the ultrasonic noise inducer occurs
during or after the installation of the horizontal-axis wind
turbine, wherein the power for the ultrasonic noise inducer comes
from the wind turbine itself, or an external source.
* * * * *