Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
This invention relates to an improved runner
type wind turbine. More particularly, this invention is
directed to an apparatus which utllizes the kinetic
energy of freely flowing masses such as air. The natural
05 energies contained in such fluids are infinite and inex-
haustible and the present invention provides an assembly
which permits the efficient recovery and control of the
energies contained in such flow-fields~
Although the runner-type turbine is described
in this disclosure as using wind only, it is not a
limiting factor and the same principles could be used to
extract the energy from free-flowing water masses such as
rivers and tidal or oceanic currents. Wind, however,
will be used as flowing media to illustrate the
invention.
~ind power has been known to humanity fox a
very long time and using its power, man moved upon the
water for thousands of years. However, it is not only at
the sea that the power of the wind has been put to work.
on land, it has been used to run simple machinery for
grinding wheat (hence named "windmills") or for pumping
water.
All windmills are energy-conversion units and
have one common item, namely a rotor or rotating part
that converts wind power into the power of a rotating
shaft. The rotor is also called a propeller or "wind
turbine" and will be referred to as such in this dis-
closure. The first windmills were built with a vertical
shaft and flappers revolving around this shaft similar to
the revolving door. This more familiar type of windmill
has been used for a long time; in Europe mills were built
on a central post so that they could be turned to face
the wind. The horizontal shaft was turned by the vane.
When the mills got too large, they were built with a
revolving turret on top. This turret housed the shaft
activated by a rotor and gear box. They featured big
four-bladed rotors, rectangular in shape, facing the
wind.
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More recent developments of entirely different
design have come into use. Water pumping windmills
required a high starting torque and to help devel~op this
torque, the rotor became multi-bladed, and was installed
05 on tall towers and utilized a circle of sheet-metal
vanes. It was also equipped with a rudder to keep the
mill facing up-wind. However such multi-bladed rotors
were not built to utilize high speed winds and had to
operate at low-tip speed ratios. Once the rotor builds-
up some rotational speed, the blades fall into the "wake"
or disturbance from preceding blades and the airflow
becomes blocked by the rotor with the result that little
power is produced.
Through the use of wind energy systems over the
centuries, the propeller type wind turbine has been
developed and put into operation. The rotor known as a
"Jacobs" rotor is the one that is almost universally used
today. It features two or three narrow blades that
resemble aircraft propeller blades. These are high speed
type of turbines operating at high tip speed ratio;
however their starting wind speed is relatively high,
approximately 8 mph,
The above mentioned rotors are horizontal-axis
machines. A major draw-back of such machines is that the
plane of rotor rotation must change to follow the wind
direction changes. This is actually accomplished by
using a "tail-vane" in the form of a vertical blade
located to the rear of the rotor, which forces the rotor
to rotate around a "Pivot" to face the wind. The high
rotation speed of the rotor generates a gyroscopic
effect, which resists any changes in direction to face
the changing wind direction.
All previously described systems have the axis
of rotation parallel to the direction of the wind.
Accordingly, in recent years a number of vertical axis
rotors have been developed as an alternative source of
converting kinetic energy contained in ambient wind
22q3
stream, into shaft rotational energy. These machines
have the axis of rotation perpendicular to both the
surface of -the earth and the wind stream. Vertical-axis
rotors have an advantage over horizontal-axis units in
05 that they do not have to be turned into the wind. These
include the known Savonius, Darrieus, and Cycloturbines.
The "Savonius" rotor has blades that are "S"
shaped in cross-section. While it is virtually self-
starting, it has a relatively poor efficiency rating.
The "Darrieus" rotors have curved blades with
"troposkein" shape, that is the shape of blades in the
shape of rotating flexible cable and which are formed in
its cross-section as an air-foil. The rotors of this type
have low starting torque at relatively high wind speed,
similar to the propeller type, however, they boast high
"tip" to "ting" speed rotation and thus have relatively
high power output. They are omni-directional but not
self-starting, and require a starter motor to bring the
rotor up to speed when a sensor indicates the wind speed
is ade~uate to produce power.
The "Cyclo" turbines (or gyro-mills) have
several vertical blades accepting wind from all
directions without orientation. It is also self-
starting; however the efficiency is low and the tip-speed
ratio is relatively low.
Many of the vertical axis machines are
inefficient, since during rotation, the rotor blades must
cut back into the wind stream, which tends to retard
their rotation, leading to an inefficient power
extraction.
All of the above mentioned types of wind
turbines are limited in the type and concept of rotor
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design. They can be built with horizontal or vertical
axis respectively, but the position of the power shaft
and of rotor is influenced by the turbine design.
A further serious limitation of the state of
05 art of the present wind turbine design is the fact that
generally only one rotor can be mounted on one shaft.
One exception is in the twin-impeller wind machine, in
which one impeller is placed behind the other in a
parallel, vertical plane.
The efficiency of such machines is not much
higher than that of a single rotor, since both use the
same wind-field cylinder, while rotating in opposite
directions.
The only means to increase the power output of
the present wind turbines is to increase their diameter,
or blade height, which inherently increases the failure
factor due to high mechanical stresses on the blades and
the tower.
The foregoing type of appara-tus highlights the
fact that present wind powered turbines are machines
placed in wind stream current to convert kinetic energy
of wind stream into a rotation and power using direct
force oE that current as it moves past a rotor or
impeller.
In theory, the performance of un-shrouded
propeller-type wind turbines (or other existing units) is
based on consideration made by "Betz" momentum theory,
which relates to the deceleration in air traversing the
wind turbine rotor and by Drzewiecki's blade-element
theory which relates to the forces produced on a blade
element. These theories are based on an observation that
the column of air arriving at the wind turbine rotor with
a velocity "V" is slowed downl and its boundary is an
expanding cylinder. The reduction of wind velocity at
the turbine rotor is usually expressed as an
'linterference" factor, "a". The
o
axial momentum analysis further shows that behind the
turbine rotor the interference factor is increased to a
value of "2a".
The available maximum power in a wind current
05 is obtained from slowing-down of the air and the recovery
of the kinetic energy flowing through a given area per
unit of time. Using all of this available power would
represent a 100% efficiency factor of the wind turbine.
In existing wind turbines, the area of concern
is the frontal area swept by the rotating blades.
Depending upon the wind velocities, the number of blades
and their configuration and shape, a great quantity of
air current is lost, so that it does not participate in
useful power conversion.
The power originally contained in an air
cylinder can be expressed in general as P=1/2 R2SV3.
Reduced to atmospheric conditions prevailing at sea level
and standard temperat.ure, this formula can be simplified
-to P=t2.14xlO ) xV xA, where "A" is an air inlet (rotor-
swept) area, and "V" is wind velocity. However the
actual work obtained by existing wind turhines is reduced
to P=(2.1~x18 6)x~xV3xa~1-a). From both equations, it
may be seen that the power obtained by the present ideal
wind turbines is at maximum when a=0.333, in which case
actual power which can be obtained by such a turbine is
P=59.9% of the power originally contained in a given air
column. Thus the "Betz" power coefficient, as it is
generally called, has a theoretical maximum of 16/27 or
59.2% of original wind power disregarding, however,
rotational and drag losses. This is of course the "power
coefficient" of an ideal wind rotor with infinite number
(zero-drag) of blades and non-shrouded propeller (or
multi-bladed "American") type of rotor.
In practice there are some side effects which
cause a further reduction in the maximum attainable
power coefficient, such as: the rotation of the wake
behind the rotor, a finite number of blades and a drag-
lift ratio larger than zero. There are certain math-
ematical and physical relations existing between power
05 and rotational speed of wind rotor, and also between
torque and rotational speed. Based on actual wind-tunnel
tests and on the geometric arrangement of wind turbine,
each type has a definite relation existing between power
coefficient and tip-speed ratio.
For any given wind speed, the separate relation
curves can be drawn, both for power and torque. ~owever,
these groups of curves are rather inconvenient to handle
as they vary with each wind speed, rotor diameter and
even density of the air. Therefore, the relation between
power, torque and the rotational speed is generally
considered "dimensionless" with the advantage that the
behaviour of rotors with different dimensions, geometry
and different wind speeds can be reduced to two formulae.
One representing power coefficient "Cp" versus
"~ " (tip speed ratio).
Power Extracted ~y Rotor
Cp = Theoretical Power Contained in Wind Cylinder
Rotational Speed of Blade Tip
and "~ " = Wind Velocity
and the second representing the torque
coeffici~nt: CD = Ac-tual Torque Obtained by Ro-tor
Theoretical Torque
and the "Cp" and IICD" are related by an expression
stating that Cp = CDx ~ , thus by knowing Cp, torque
coefficient CD can be calculated and CD versus ~ curves
can be drawn.
As disclosed hereinafter, different curves for
horizontal and verticaI rotors, two-bladed and multi-
bladed arrangements are shown. One can clearly deduct
from these diagrams that the multi-bladed "American"
rotor operates at low tip-speed ratio, and two or three-
bladed rotors operate a-t high-tip speed ratios.
~: :
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Thus, -the maximum power coefficient tat the so-
called design tip-speed ratio) does not differ all that
much but there is a considerable difference in torque,
both in starting -torque (tip-speed ratio = 0) and in
05 maximum torque.
Another significant factor is that the multi-
bladed "American" rotor, "Savonius" type, and Eour-bladed
"Dutch" rotor all reach their top power coefficient at
low wind speeds, and that the power extracted from the
wind at higher wind velocities falls down to zero
relatively quickly.
The two or three-bladed rotors have a "power"
factor slightly higher but the starting wind speed is
much higher (usually at 8 mph), therefore the rotational
speed is high for the same power factor, however starting
tor~ue is low and this poses certain limita-tions on the
use of presently built bladed rotors.
It can be appreciated from the above discus-
sions that the wind velocities and therefore their re-
lated kinetic energies are the leading factors to be
considered while constructing any wind kurbine.
It is well known that on different continents,
one can observe well defined groups of wind ~elocities,
which predominate and are called "prevalent" (frequent)
winds. There is also a well defined group of winds which
contain the bul]c of the energy called "energy" winds.
~sually the prevalent winds blow five out of seven days,
the energy winds blow two out of seven days (or 28%).
The velocities of energy winds are approximately 10 to 15
mph, the most frequent prevalent wind is estimated at 3
to 8 mph.
Therefore a desirable wind power extracting
device should be able to operate and have a well reg-
ulated power output using all the above winds, since
the prevailing winds produce about 3/4 of the total wind
energy over a given time period. Even during a calm
summer month, 70% of the energy comes from the winds
which blow only 28% of the time.
220
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Considering the foregoing observations and
taking into account the operational data, as described
hereinafter, of present wind turbines, one can conclude
that at -the same wind speed and same rotor diameter, a
multi-bladed "~merican" turbine would reach its peak
05 operating performance at tip-speed ratio = 1 and the
power ratio = 0.3, resulting actually in a low number of
rotor revolutions. A further increase in tip-speed ratio
means an increase in wind velocity and -the number of rev-
olutions of the rotor resulting in a turbine performance
falling down to zero.
A propeller type rotor has a starting wind
speed well above the point where the "American" multi-
bladed rotor is not delivering any power. The power
coefficient versus tip-speed ratio curve of bladed type
of ro-tors is more ~lat, therefore it can accep-t higher
wind speeds with almost the same power coefficient.
It can be appreciated from the foregoing dis-
cussion that little has been accomplished in the present
state of art oE wind turbines in the way of molding,
shaping, redirecting and rearranging the incoming wind
stream upon the rotor in such a way as to avoid the
shortcomings of multi-bladed or propeller type rotors.
Thus it would be desirable to obtain a wind turbine rotor
which would incorporate the advantages of both types,
while actually supplying a link between these two types
of existing rotors.
To exemplify the above, reference may be had to
the prior art relating to turbine blades; US 4,596,367
discloses a device which, as a modular unit, includes a
pair of triangular vanes arranged ln a staggered,
:
.
2~)
g
overlapping relationship and joined together along an
interconnecting panel. The triangular pockets form a
"scoop" so that the device, when rotating about a central
axis, presents a first and then another of the triangular
05 pockets to a wind flow.
US 4,522,600 discloses a blade arrangement
composed of three curved sheets, one end of which is
journalled on a shaft. Other than being a planar curved
outline, no structure is imparted to the sheets so that
the latter merely appear to act as a wind "stop".
US 603,703 discloses triangularly shaped
propellers, similar in structure and configuration to a
"scoop". In the arrangement shown, a plurality of these
triangular propellers are journalled on a shaEt. A wind
stream is adapted to enter the narrower front portion and
be discharged from the wider outlet, the air being dis-
charged being directed into the next propeller.
US 1,213,955 has (in Fig. 2) a configuration
which is best illustrated in the blank form. When folded
to form a fan blade, a "scoop" having a very large side
for the fan is formed, with the opposed side being either
of a minor triangular configuration or oE a "tab" out-
line. Different configurations for pairs of blades,
mounted in tandem, are possible depending on which side
of the blank is folded over the principal axis.
Australian 145,276 discloses cylindrical hollow
bodies, much in the form of a tube, and relies on a cen-
tral cap to deflect wind into the hollow bodies.
French 547,884 discloses a windmill with blades
which have an arc-shape. AS noted therein, the contour
of the blade structure is such that it has a further arc
extending in a principal flow direction.
Italian 492,199 discloses a plate-type arrange-
ment r in which "hook-shaped" projections extend above the
plane of the plate in order to catch wind flows.
~LZ9~
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~S 2,996,120 discloses in Figure 4 parallelo-
gram-shaped blades, partially of a closed structure, in
cross-section in which the air flow enters a mouth into
the closed parallelogram-shaped cross-section forming a
05 discharge outlet.
A wind wheel is disclosed in US 552,164 in
which the blades have a major surface with an upstanding
and curved smaller triangular flap extending into a por~
tion of the blade.
US 220,083 discloses a windmill, in which the
blades are curved lengthwise and provided with an
inclined flange on the outer edge. This inclined flange
appears to provide a greater inlet area to capture a wind
flow; this type of structure does not permit a vertical
arrangement and as well, does not provide any radial wind
deflection and depends on a different type of air-flow
around the blades to generate power. In a further patent
of ~artin, US 207,189, again no vertical arrangement is
possible and no radial wind deflection can be obtained.
In accordance with one aspect of this inven-
tion, there is provided an improved turbine blade which
is suitable for use in a wind turbine for harnessing
power from wind~ More particularly, in accordance with
one form of the present invention, the turbine blade is
adapted to receive a flow of air from a wind stream at an
inlet portion of the blade and deflecting the air via the
blade to an outlet portion thereof, the blade comprising
a body having a pair of opposed major planar surfaces and
a generally conoid shaped configuration with a pair of
opposed open ends, one end forming a discharge outlet
with a cross sectional area of the conoid-shaped body
proximate the discharge outlet being less than the cross-
sectional area intermediate the discharge outlet and the
inlet portion, and
~z94~20
deflecting means for deflecting a fluid flow ~rom the
outlet in a direction angularly disposed relative to the
normal fluid flow established by the conoid-shaped body.
In accordance with a further aspect of the
05 present invention, there is provided a method of recov-
ering usable energy from a moving fluid stream having in
one form a principal fluid flow in a primary first dir-
ection comprising disposing a conoid-shaped body in the
fluid flow, the conoid-shaped body having a hollow
interior in which the hollow interior faces the fluid
flow direction, intercepting a first component of fluid
flow of the fluid stream in an inlet portion of the
conoid body to deflect the first component and angularly
to the principal fluid flow direction of the fluid
stream, angularly intercepting a second component of the
fluid flow within the conoid-shaped body and deflecting
the intercepted second component in tangentially of the
fluid flow direction, combining the axial fluid flows of
the first and second components, causing the combined
axial flow to pass through an area of reduced cross-
section, and deflecting the combined axial flow in a
direction tangentially disposed relative to the principal
direction of the combined ax.ial flow.
In a still further embodiment in the present
invention, there is also provided a blank suitable for
use in a turbine blade, which blank comprises a sheet of
non-flexible material, the sheet having a generally
planar configuration with a pair of opposed major
surfaces, the blade and a first side forming an arcuately
contoured inlet edge for the body, a lateral side
angularly disposed relative to the contoured first side
and extending backwardly and outwardly therefrom, a
: second lower side angularly disposed relative to the
L22~:3
-12-
first pair of sides and extending inwardly and rearwardly
of the body, and being angularly disposed to the deflec-
tor when the deflector is included, and to an axial line
of the blade, and a rearwardly projecting recess between
05 the sides, the blade being adapted to bend along an axial
line extending between the first arcuate side and said
last mentioned side to generally a conoid configuration.
The second lower angularly d.isposed side of the blade
forms the incoming radially deflected air and causes it
to flow around to the backside of the blade in a fashion
similar to an airfoil contour, thus creating a pressure
differential between the inside and the outside of the
blade.
In further detail of the present invention, the
blank used to form the turbine blade, and the blade
formed therefrom, may be made of any suitable material
capable of withstanding the forces encountered for its
intended operation. Typicallyl these will be metals of
various types, or alternately, cast or molded plastic
mate.rial. In the ca~se of sheet materials, normally these
will be die-cast or stamped into blanks of the approp-
riate shape, and subsequently contoured to form a conoid-
shaped body according to the structure of the present in-
vention. With respect to metallic materials, these may
also be die-cast if desired. Typical metallic materials
include aluminum, steel, copper or the like: in the case
of plastic materials, the blade may also be formed from
various types of polyolefins or copolymers. Also, plas-
tic coated canvas or the like materials can be used.
The turbine blades of the present invention, is
explained hereinafter in greater detail, may be used in
structures varying from small portable units to rela-
tively large stand-alone structures. Typically, a plur~
ality of blades eg. ten(lO) to thirty(30) or more,
12~2~0
are arranged on a suitable supporting structure, oriented
so that the hollow body portion of the conoid configur-
ation is adapted to face the principal direction of the
oncoming fluid stream, and the blade assembly is then
05 permitted to rotate about a fixed axis in the direction
of rotation caused by the oncoming fluid stream. To this
end, the individual blades are preferably provided with
mounting means (such as lips or the like) to permit the
individual blades to be fastened to an assembly; alter-
nately, it is also possible to a supporting member to
form an assembly-this assembly may be die-cast with the
blades and other components as described herein as a one-
piece structure, which is particularly appropriate for
smaller sized units.
When the blades are provided with mounting
means, a supporting sub-structure will be provided for
arranging the blades to be mounted in a front-to-rear
alignment; for most efficient operation, the blades are
mounted in such an alignment in a relatively close rela-
tionship.
The overall arrangement of the blades on a
supporting structure can var~ considerably, however two
or more rows oE blades, as well as two or more sub-
assemblies, each carrying one or more rows of turbine
blades, can be mounted on a single assembly. In this
manner, a plurality of such sub-assemblies may be used
with a common supporting apparatus to increase power
generation. Likewise, two(2) or more assemblies may be
coupled together, each assembly having two(2) or more
sub-assemblies with the turbine blades thereon.
One aspect of the blade design is that it can
be assembled in a radial direction as described herein or
can alternately be mounted axially directly in the path
of an air or fluid flow without any fluid deviation. The
blade axis may have an individual wind stream deflecting
system to decompose the axial flow into three different
vectors, and can be thus mounted on circular
~L2~
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rings including mounting of the blades in the central
area of a circular ring. Each circular ring may have a
variable diameter, which may be variable as well as being
axially inclined to handle increased circumferential
05 Speed.
The turbine blades of the present invention are
particularly adapted for use in wind turbines, but may
also be used for liquids such as water-ie. in water
turbine structures. Since most turbine blades find
application in wind the turbine technology; reference to
the blades and structures to the present invention as
wind turbine technology will be made in describing
further features.
Also, the turbine blades of the present
invention are suitable for use in a wind turbine for
receiving a flow of air from a wind stream at an inlet
portion of the blade and deflecting the air via the blade
to an outlet portion thereof, the blade comprising a body
having a generally conoid-shaped configuration with a
pair of opposed ends, one end forming a discharge out-
let, with a cross-sectional area of the conoid-shaped
body proximate the discharge outlet being less than the
cross-sectional area intermediate the discharge outlet
and the inlet portion, the body having a pair of opposed
sides with the body having an axis of symmetry excluding
between said inlet and outlet portions.
Correspondingly, there is provided a method of
recovering energy ideas from a fluid stream using the
above blade, as described hereinafter in greater detail.
In preferred embodiments of the invention, the
conoid-shaped body is desirably provided with a first
pair of spaced-apart lateral sides adjacent or at the
inlet portion of the blade, which sides have three
lateral edges which are angularly disposed relative to
the inlet and which extend outwardly and upwardly/
rearwardly of the inlet. Preferably, these lateral sides
extend,
Z~
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in the contoured blade configuration, downwardly from the
conoid-shaped body and are identical so as to form
parallel, or substantially parallel opposed side portions
of the body. In addition to the inlet section of the
05 conoid body, this first pair of sides also defines an air
inlet portion for the turbine blade, which functions to
capture a component of an air stream and direct the same
toward the interior of the conoid body. Generally
speaking, these side panels terminating at the first pair
of spaced-apart side edges will be obliquely disposed
relative to the air inlet, thus providing a greater
cross-sectional area from the mouth or inlet of the
conoid body, which preferably increases from the inlet to
a point intermediate the inlet and discharge openings of
the conoid-shaped body.
The conoid-shaped body is also provided with a
second pair of sides intermediate the discharge opening
and the first pair of sides and in an assembled form, the
second pair of sides preferably is disposed at an acute
angle relative to the inlet. The second pair of disposed
sides oE the conoid body also intersects the first pair
of disposed sides, again in an angular relationship
thereto, and defines an area of greatest cross-section
for the conoid body at the point of intersection.
However, not all forms of the invention need be limited
to the area of greatest cross-section being located at
the point of intersection of the first and second pairs
o~ sides, as beneficial results will still be obtained
where the area of greatest crosssection of shape of the
conoid body is not at the point of intersection.
According to the present invention, improved
results in terms of power recovery are achieved by
providing the turbine blade with deflecting means for
defIecting an axial flow of air along the conoid body at
the discharge end of the device. To this end, the
deflecting means is effective to deflect the a~ial flow
~0
z~
-16-
of air being discharged in an amount preferably of up to
abou-t 35 relative to the axis oE the axial flow through
the conoid-shaped body, and most preferably between 10
to 30. Although this may vary, by creating a deflected
05 exhaust flow of air from a turbine blade, it has been
unexpectedly found that this will contribute to an
increase in efficiency of the turbine blade which in turn
results in eg. higher power outputs. It is thought that
this is due to the fact that the deflected exhaust air
can be removed from the environment surroundlng the
rotating turbine blades in a more efficient manner, so as
to avoid interference with the flow patterns of the
surrounding atmosphere.
In preferred embodiments, the deflecting means
preferably deflects the air in an air flow having the
general configuration corresponding to that prior to
deflection, and thus avoid loss of power due to changing
cross-sections at the discharge point for the exhaust
air. ~owever, it is not essential that the profile of
the deElected air flow be specifically axial prior to
being deflected; in larger installations, using large-
sized blades, diferent profiles may be employed Eor
different purposes where it is desired to re-direct spent
or exhaust air from a structure -through, eg. secondary
exhaust arrangements.
The deflecting means may be an extension or a
part of the exhaust or discharge outlet of the -turbine
blade; to this end, the conoid-shaped body may continue
with an extension thereof, appropriately angled, exten-
ding into the air stream flow. It is important to note,
in accordance to the present invention, that when the
deflecting means acts upon an axially-flowing air stream,
that the complete or total cross-section of the air
stream need not be deflected. In practice, it has been
found suitable to use deflecting means which extend into
the path of the axially flowing s-tream at the discharge
outlet to only a depth ranging from S% to 10
~2~2~)
-17-
of the depth of the outlet, and angled between 1 to 90,
in order to achieve the improvements of the present in-
ven-tion. In this respect, the deflecting means prefer-
ably forms an extension of, and is int~gral with, the
05 interior surface of the conoid-shaped body.
In the above described embodiments, the blade
most desirably has a three-dimensional air inlet with a
first body portion lying in a first plane and being
formed at least in part by a first leading edge and a
second body portion formed at least in part by a second
edge and lying in a plane space from the first body
portion, both the first and second body portions being
joined by an intermediate body portion of a generally
arcuate configuration. In this form, the blade also
desirably has a three-dimensional air discharge outlet at
the outlet per se with a first discharge body portion
lying in a first plane, and a further body portion form-
ing a part of the discharge air of the blade lying in a
second plane spaced from the first plane, and an inter-
mediate discharge body portion in the second plane and
forming a generally arcuate tapered configuration.
A wind turbine assembly of this invention
comprises a plurality of the blades mounted on an air or
fluid flow deflector, the deflector being operatively
associated with a power take-off means, with the means
for deflecting the air being operative to direct an air
flow into the inlet area of the blades.
In the above assembly the means for deflecting
the incoming air to the blades may take the form of an
air deflector adapted to deflect the incoming air rad-
ially through a plurality of blades mounted circumfer-
entially of the deflector. The assembly may include an
air shield at least partially covering the blades.
Having thus generally described the invention,
references will now be made to the accompanying drawings,
illustrating preferred embodiments and in which:
220
-18-
Figure 1 is a schematic view showing a fluid
flow field around known two or multi-bladed rotors;
Figure 2 is a schematic cross-sectional view of
a runner-type rotor encompassing the present invention;
05 Figure 3A is a side view of one form of turbine
blade of the present invention;
Figure 3B is an end elevational view taken
along the arrow B of Figure 3A.
Figure 4~, 5A and 6A are perspective views of
the blades of the present invention showing the different
fluid actions on the blade;
Figure 4B, 5B and 6B are vectorial views of the
frontal impulse, impulse and reactive t~pes of action of
a fluid on the blade;
Figure 7 is a chart diagram comparing the power
coefficient of various turbine configurations relative to
the tip speed ratios oE various types of turbine
configurations;
Figure 8 is a diagram illustrating the torque
coe~ficient relative to the tip speed ratio of various
types of turbine configurations;
Figure 9 is a chart di~gram showing the power
curves oE newer -type turbines at low wind velocities
compared to known blade--type turbines;
Figure 10 is a schematic outline of a -turbine
with a horizontal axis configura-tion;
Figure 11 is a schematic outline of a runner
type turbine with a vertical axis;
Figure 12 is a schematic outline of a one rotor
30 : disc type turbine with a vertical power take-off shaft
and a pair of blades mounted in a back-to-back manner;
:Figure 13 is~a perspective view of a runner-
type turbine utilizing a horizontal shaft with one
particular orm of blade as in Figure 3A and Figure 3B;
: Figure 14 is a perspective view of a runner-
: type turbine utilizing an inlet concentrator and a
frontal shroud attached to the blade and rotating with
the blades, the blades of the form in Figure 3B;
;
~2~ 0
--19--
Figure 15 is a perspective view of a runner-
-type turbine utilizing a vertical axis and with a movable
air-inlet elbow, again with blades of the form in Figure
3B;
05 Figure 16 is a side elevational view of a blade
having a modification according to the present invention;
Figure 16A is a section taken along the line
XVIA of Figure 16;
Figure 16B is a section taken along the line
XVIB of Figure 16;
Figure 16C is a section taken along the line
XVIC of Figure 16;
Figure 17 is a partial elevational section
showing the blade of Figure 3B in a two tier arrangement;
Figure 18 is a partial sectional view showing a
modified arrangement in the application of the device of
the present invention in generating electrical current
for a distillation~purification system;
Figure 19 is a perspective view of an alternate
blade according to the present invention;
Figure 20 is a section taken along the line A -
A of Figure 19;
Figure 21 is a section taken along the line B -
B of Figure 19; and
Figure 22 is a section taken along the line C -
C of Figure 19.
Referring now to the d:rawings in greater
detail, and initlally with respect to Figures 3A and 3B,
there is illustrated a turbine blade according to the
present invention; the blade preferably comprises a one-
piece body indicated generally by reference numeral 20,
having a leading edge 22 which forms an air-inlet for the
blade~ Leading edge 22~, as will be seen from Figure 3B,
has a generally arcuately: shaped outline and in the Eorm
shown, forms with side edges defined hereinafter, a
three-dimensional air-inlet.
zo
-20-
Side edges 28 are angularly disposed relative
to -the leading edge and also form, in particular
configuration illustra-ted, a portion of the air-inlet for
-the blade. The edges 28 are adapted to mount the turbine
05 blade to a turbine, again as described hereina~ter in
greater detail.
The body of the blade 20 terminates in a three-
dimensional outlet again in the configuration shown, and
is provided with a trailing or discharge edge 30
preferably angularly displaced relative to the leading
edge 22 as well as the side edges 28. Edge 30 together
with side edges 28 form a semi-conically shaped air-
outlet Eor the body in the form of a three-dimensional
outlet.
Each blade generally forms a conical
configuration with the base oE the cone forming the angle
as shown in Figure 3A.
From the above description, the blades will be
seen to basically have a conoid shaped body in which the
body includes a pair oE opposed sides edges 28 with an
arcuate leading edge 22 joining such sides. The blades
are mounted on their side edges.
Referring now to Figure 1, illustrating a
typical prior art arrangement, involving two or multi-
bladed rotors, it will be seen that a fluid, such as a
flow of air or wind, which is used hereinafter to
illustrate the apparatus of the present invention,
approaches the inlet of a typical device and is induced
to a circular motion and subjected to radial acceleration
in a plane parallel to the rotor's plane. Thus, the flow
of wind, indicated by the arrow 50, initially enters the
turbine structure with the wind-stream having a diame-ter
indicated generally by the line 52.
Within the turbine assembly, the propeller
blades 54 are mounted on a suitable power take-off shaft
5~; as will be seen from Figure 1, studies have shown
that there is an unused air-stream indicated by the
shaded lines 58. In this respect, the rotational speed
~9422C)
-21-
of the blades 54 results in a rotational character o-E a
windstream approaching the rotor; thus an air cylinder at
the rotor plane expands due to the centrifugal forces
imparted to it and approximately forty percent of the
05 kinetic energy is lost by this phenomenon, known as the
Betz coefficient. The rotation of the wa~e behind the
rotor also results in additional kinetic energy losses
and a lowering of the power coefficient. Also, given a
finite number of blades, in place of an infinite number
of blades, will cause an e~tra reduction in power,
particularly at low tip-speed ratios. This is due to the
pressure leakage around the tip of the blade, Eorming
cross-flow around the blade tips.
As will also be seen from Figure 1, the various
velocity factors are shown at the different locations for
a conventional arrangement. In Figure 1, and in the
above description, the term "expanding cylinder" refers
to the orm oE the column of air arriving a-t the rotor
with a velocity "V~" is slowed down - thus forms the
"expanding cylinder".
Referring now to Figure 2, and the blades as
previously described, an apparatus according to the
present invention comprises a plurality of the blades 20
mounted circumEerentially and peripherally about air
deflecting means which is in the form of a disc 60 which
in turn, is connected to a power take-of shat 62 and
which may be connected to various devices according to
conventional technology. The disc 60 preferably
comprises a one-piece 1at member and may be made oE any
suitable material Eor the purpose; disc 60 mounts the
blades 20 along the edges 28 ~see Fig 3B) by suitable
means - e.g~, rivets, screws, or the like as indicated
generally by reerence numeral 66 (See Figure 3A).
The assembIy of the blades about the
circumference of the disc 60 is generally made so that
the leading edges of a given blade overlap with an
adjacent blade; by mounting the blades in this manner, a
mass of fluid-flow is thus forced, ater being deflected
2~
-22-
by the deflecting means to participate in energy
conversion, and consequently impinge upon the rotor
blades. By mounting the blades in the preferred manner
as illustrated, the deflected air coming inwardly, as
05 indicated by the arrows 82, impinges on the blades
radially, circumferentially and outwardly relative to the
disc plane. Thus, the air-flow indicated by arrows 82
assumes the configuration indicated by arrows 84 and i5
passed to the three-dimensional inlet of the blades.
The mounting of the blades, and their
configuration according to the present invention,
provides for the use of the incoming air to radially,
circumferentially and outwardly impinge on the blades to
obtain a high degree of efficiency. This will be evident
from diagrammatic Figures 4A through 6A, which illustrate
the advantages of the special shape of the conical
contour which radially extends away from and on an angle
to the disc relative to its outer periphery and plane.
From these Figures, deflected wind segments impinge on
each individual blade and produce a reaction and impulse
Eorce by changes in the flow-velocities of the wind and
directions as indicated in the drawings; it will be seen
that the force vectors of the impinging air-stream are
individually imparted to the blades and that they are
complimentary to each other. Thus, Figure 4A illustrates
the radial wind segment direction relative to the blade
20 with the arrow 100 indicating the radial segment. In
this manner, as will be seen Erom Figure 4B, with the
arrow 102 indicating the radial wind velocity from the
centre of the turbine arrangement, the diagram
illustrates that there is a radial wind velocity VR with
Vl indicating the wind velocity relative to the blade 20.
V2 indicates the circumferential wind component; L is the
lift force and T is the thrust force with Ql being the
useful torque force.
In Figure 5A, again due to the configuration of
the blade, the radial wind segment indicated by the arrow
100 also generates a further configuration ~See Figure
22~
-23-
5B) where a portion of the wind is deflected and in this
case; the radial velocity (VR) component also has a Vl
wind velocity relative to the blade and V2 velocity which
is perpendicular to the disc 60. Q2 thus defines the
05 useful tor~ue force.
The third force acting on the blade 20 is
illustrated in Figures 6A and 6B with the wind segment
being indicated by the arrow 104. As illustrated in
Figure 6B, the force for the radial wind velocity VR
includes Vl which is the wind velocity relative to the
blade 20, V2 which is the circumferential wind component;
R which is the force perpendicular to a line a b; L is
the lift perpendicular to Vl and D is the drag (parallel
to Vl). The thrust T is shown by the arrow therein and
the resulting torque force indicated by Q3.
Consequently, from the above, the total force
acting on each blade is equal to the sum of Ql plus Q2
plus Q3-
.~t will be thus be seen, from the above
description, that with the blades and the turbine
assembly of the present invention, the phenomena
described above are purposely e~ploited by specifically
diverting an airstream from its horizontal flow to form
an expanding, radial flow-field. Thus, a runner-type
turbine is utilized with the Elow-fields as indicated in
Figure 2, created by a disc which deflects an incoming
air-flow, preferably in a direction perpendicularly to
the direction of the air-flow. An air-flow, entering the
turbine structure, thus strikes the disc and is deflected
perpendicularly and discharged radially and parallel to
the disc and in this form, is basically a non-de-
energized wind strength which impinges simultaneously
during the rotation of the blades 20. The blades, due to
their configuration and structure, substantially a~oid
any dissipation o~ kinetic energy which would otherwise
result in power losses for the inlet area and
substantially the complete mass o~ the wind stream is
.
~2~ ~Z~
-24-
thus forced to participate in energy ~onversion. In this
manner, the wind s-tream thus impinges as described above,
namely in a radial, circumferentially and outwardly
extendlng direction relative to the disc 60.
05 It will also be seen that the rotational speed
of the blades result in a rotational character of the
wind stream as it approaches the rotor; thus an air
cylinder or cone, preferably expandsl and aids in the
displacing of the incoming wind stream.
In the preferred form, it will also be seen
from the above description that the diverted wind stream
runs generally parallel to the disc 60 and is broken down
at the blade area into three circumferential vectorial
components over each blade; the circumferential
components of wind velocities impart to the rotor i-ts
rotating motion and thus furnish the useful torque to the
disc and shaft.
It will also be understood from the foregoing
that due to the structure disclosed herein, the apparatus
disclosed herein can have the blade -tip's circumferential
speed at any speed diferent to -the primary wind speed
and thak the ratio to each other will thus not have the
same efficiency meaning as is the situation with e~isting
fluid turbines.
The relative wind velocities and the vectorial
decomposed elemen-ts produce a reaction and impulse force
on each blade by the changes in the flow direction and
velocities around the air-foil, with the result that the
dynamic pressure on the air-foil blade facing the wind
streams segment is lower on the reverse or down-wind
side. The relative wind speed and forces acting on the
blade are thus formed by three components, namely (1) a
radial or frontal deflection impulse; t2) an impulse
force due to the blade curvature; and (3) a lift force
due to the air dynamic air-flow around the air-foil
configuration. Thus, the construction and shape of the
blades of the present invention, the deflecting angles,
-25-
the number of blades and the diameter of the blades are
diEfering parameters utilized in the present inven-tion in
the conversion of energy using the turbine of the present
invention. An in-flowing fluid energy stream, after
05 completing its func-tion relative to the blades, must exit
from the turbine effectively and without substantial
resistance and with substantially the same volumetric
flow which is equal to the inlet stream. For this
reason, the three-dimensional blades and their rotation
provide the required requisities for this purpose; as
otherwise disclosed herein, the three-dimensionally
shaped blades and the rotation provide an enlarged exit;
the configuration as described in Figure 2 where V out is
smaller than V ~ ; as will also be seen from Figure 2, the
blade inlet area shown therein as hin is smaller than the
discharge area hoUt. The amount of the difference
between the blade inlet area and the blade outlet area,
or inlet versus outlet, will vary depending upon the -type
oE fluid ~low, the size of the blades, the blade
diameter, etc. and may range from 10% or more in volume
to 50% or more. These factors will be chosen, as
indicated, depending on the particular application, the
number o blades etc.
Referring now to Figures 7 and 8, a comparison
between a wind turbine, re~erred to as a "runner" type
rotor, of the present invention, and various conventional
arrangements, are illustrated graphically. With ref-
erence to Figure 7 ~ the power coefficients' curves for
the various arrangements are illustrated, relative to -tip
speed ratios, and in which an apparatus of the present
invention constructed according to Figures 2 et. seq.,
was utilized.
As shown in Figure 7r there is a theore-tical
ideal curve for known rotors indicated by the curve 120
and the known outputs for various arrangements ar~
illustrated by the curves 122, 124, 126, 12~ and 130.
The power coefficient curve for the apparatus of the
present invention, illustrated by curve 134, illustrates
~ 2
-26-
a desired "through-flow" capacity for air. At low wind
stream speeds, meaning low values of ~, the power and
torque factors increase with increasing tip-speed ratios.
~ further increase in the wind velocity does not produce
05 the same increase in the rotational speed of -the rotor
and a "power coefficient" versus the tip-speed ratio
curve for the runner type of turbine shows mark~d dip.
This phenomena is related to the "choking" effect of the
blade rotation and can be explained by the law of
continuity expressed by the volumetric flow rate "FR"~
the wind velocity "V" and through-flow area "R", which
are related by the simple law: FR = ~ x R, stating that
the mean ve]ocity of the flow of any fluid through any
given area is a function of its volume. ThereEore the
blades through-flow area is able to absorb and release
only a certain volume of air which increases with the
wind velocity and the increased rotational speed, until
the optimum value is reached.
Any increase in the wind velocity and
therefore, any increase in the rotor's revolutions will
produce a partial "through-flow" blocking effect by the
blades and thereEore an increasing resistance to the
air-flow, resulting in a reduced volumetric flow-rate
through blades and a partial blocking effect to the
incoming wind-stream at the inlet of the turbine ring
and the automatic reduction of relative wind inlet
velocity. Accordingly, the turbine will automatically
reach its optimum rotational speed and any increase in
the wind speed will not affect much the rotation of the
turbine's rotor. However the static pressure build-up
of the slowed wind stream at the inlet opening to the
runner will increase the power extracted by the rotor
due to the pressure's differential increase across the
bladesO
Following the above, it can be seen that the
power factor will not fall down to zero with the in-
creased wind speed, as is the case with the known
~;29~2~)
-27-
"American" or propeller type rotors. It follows also
that the circumferential speed cannot reach critical
values as is the case with the propeller type rotors.
Obviously the drag forces on the rotor will increase
05 with increased wind velocities and appropriate steps
should be included to prevent structural damage.s.
With respect to the above discussion, it will
also be understood that the power coefficient "Cp"
tFigure 7) is a function of the geometric arrangement of
a wind turbine, determined by actual tests. In these
tests, a second parameter employed was khe "tlp-speed
ratio". Theoretically the higher the tip-speed ratio,
the higher the extracted power coefficient will be for
"perfectly" designed turbines. A wind turbine with a
two or three bladed propeller has maximum efficiency at
highe:r tip-speed ratios; a multi-bladed "American" wind
turbine has its best performance at low tip-speed
ratios. Both types of rotor arrangements have a criti-
cal rotational speed at which the wind is blocked by the
rotor and no power is produced since the blades are
followiny into a flow-distortion craated by the pre-
ceding blades.
The arrangement of the present invention
utilized for the tests illustrated in Figures 7 through
9 had a 36 in. wind-inlet diameter. From the results
shown, and although the tip-speed ratio in the apparatus
of the present invention does not have the same specific
meaning as the multi-bladed or propeller type conven-
tional arrangement, it will be seen that the power co-
e~ficient of the apparatus o.f the present invention is
at low wind velocities ttip-speed ratios) with very high
results. The unique ~low focusing and distribution
system resulting from the apparatus of the present
invention increases the extracting power as the
efficiency of the rotor above the ideal "Betz
coefficient" or limit, for non-shrouded
propeller type turbines. These
~ ~J'~c2Z~
-~8-
efficiencies can be reached and exceeded by the turbines
of the present invention. It will also be seen from the
su~marized data that this higher power coefficient is
reached at quite low wind speeds, at a low number of
05 revolutions (meaning low tip-speed ratios) or low cir-
cumferen-tial runner speeds. Compared to the prior art
known arrangements, the maximum power extraction is
reached at approximately 1/8 of the tip-speed ratio for
bladed type turbines; the tip-speed ratio compares to
those achieved by the multi-bIaded rotor but again, the
power factor of the present invention is conservatively
higher.
Following the behaviour of the power
coefficient versus the tip-speed ratio curve for the
runner-type turbine in Figure 7, it can be observed that
this curve dips quite rapidly with the increased tip-
speed ratio meaning that the increased wind velocity is
not represented by the increased revolutlon of the
turbine. However, the power factor does not reach zero
as is the case with the multi-bladed rotor, but after
reaching its lowest point, it starts climbing again,
meaning the increase of the energy extraction. The tip-
speed ratio remains at this point almost cGnstant, indi-
cating that the turbine is controlling its revolution
despite the increased wind-stream speed, keeping its
circumferential speed increase almost equal to the wind
stream increase.
As illustrated in Figure 9, it will be seen
that the power extrac-tion from an apparatus according to
the present invention, the curve of which is designated
by reference numeral 140, and taken from tests comparing
the apparatus of the present invention with a conven-
~ional propeller type wind rotor (the power curve being
designated by reference numeral 1~2) shows a very
significant improvement over the conventional structure.
In this respect, conventional structures typically have
a starting wind speed for two and three bladed wind
rotors in the neighborhood of 8 miles per hour; whereas
~0
Z20
-29-
the extracted power curve for the structure of the
present invention commences at a much lower speed as
will be evident from the graph. Thus, power is ex-
tracted under low velocity winds and the effectiveness
05 of -the runner type rotor is much higher than the
conventional arrangements.
Referring now to Figures 10 et. seq., a
modified apparatus to that shown in Figure 2 is
illustrated; in this arrangement, (where similar
reference numerals have been used to designa~e similar
components to those previously described), the apparatus
may be mounted on a swivel stand 152; a stationary axis
154 is provided for the apparatus; the apparatus may
also include a rotary or stationary wind inlet concen-
trator indicated generally by reference numeral 156
which may surround the peripheral portion of the blade
20 and which will project beyond the face of the blades
20 in a circumferential outline to direct the wind in-
wardly towards the disc 60. In a preferred embodiment,
the apparatus may also have a vane 158 to align the unit
with the wind direction. A power take-off wheel assem-
bly 160 may also be employed and the whole unit may be
mounted on a swivel shaft 162. A wind flow indicated by
the arrows ~2, after passing through the unit, is dis-
charged generally in the direction indicated by the
arrows 164.
Contrary to the horizontal axial arrangement
of Figure 10, the arrangement shown in Figure 11 utili-
zes a vertical axis and similar components. However, in
this case, a 90 elbow-concentrator capable of swivel-
ing, indicated by reference numeral 166 may be employed
for mounting the apparatus. :A shroud assembly 168 may
: be employed for mounting the unit. As will be seen, in
this case, the power ta~e-off assembly 160 is generally
mounted in a horizontal manner. A vertical
\
~LZ~22~
-30-
swivel shaft 170 may be employed for mounting the con-
centra-tor 166.
In the modified arrangement illustrated in
Figure 12, the device of the present invention utilizes
05 a single rotor disc and a pair of sets of blades in a
back-to-back arrangement utilizing a common power shaft.
In this arrangement, again with similar reference num-
erals being used to designa-te previously described
components, an inlet scoop and shroud may be utilized as
indicated by reference numeral 172. A power take-off
wheel or the like 174 may be centrally mounted on a
power-shaft 176 journalled centrally of a disc 60. In
this arrangement, a pair of spaced apart blade assem-
blies are employed indicated by reference 178 mounted
about both major faces of the disc 60.
The arrangement may also include an outlet
diffuser 180 and an air-outlet shroud 182. An air flow,
indicated generally by the arrows 184, will enter the
shroud assembly 172 and follow generally the lines
indicated by reference numerals 186 and 188 where the
assembly will thus utilize the flow imparted by the air
which is discharged in the direction indicated by the
arrow 190 through the outlet diffuser 180.
The arrangements illustrated in Figures 13
through 15 illustrate a variation of the invention.
More particularly, a modified blade arrangement is
illustrated in which the blade is provided with a
conoid-shaped body, the shape and configuration of which
will be described hereinafter in greater detail with
reference to Figures 16 et seq. Again, similar com-
: ponents are designated by similar reference numerals.
In the arrangement in Figure 13, the apparatus is
mounted on a central pivot 194 and utiliæes a vane 158.
Thus, the apparatus of the present invention, can be
mounted as a free standing unit employing a horizontal
220
-31-
shaft and a vertical disc and blade assembly without a
concentrator, housing or an outlet diffuser.
In the arrangement employed in Figure 14, a
modified horizontal axis and air-inlet with vertical
05 runners is employed and a front shroud 200 is employed.
A stand 202 mounts a power take-off shaft 204. As will
be seen, the front shroud also extends outwardly in the
direction of the wind flow to provide an inlet portion
for the apparatus as indicated by reference numeral 206.
In the arrangement illustrated in Figure 15,
again a control vane 158 is employed mounted by means of
suitable supports 210 to the unit; in this case, the
arrangement employs a vertical shaft with a horizontal
air inlet and runner disc and is mounted on a stand 214
with a vertical power take-off shaft 216. An air inlet
and concentrator elbow 218 is employed to direct an air
flow indic~ted by the arrow into the unit; a shroud 220
protects the blades ~shown partially in section) against
the incoming air with the air outlets being indicated by
arrows 222.
Referring now to Figure 16, an alternate form
of the blade is illustrated and a.s will be seen from
Figures 16A to 16C, the blade is provided with the
conoid shaped body similar to that described previously
but in this case, the conoid shaped body includes a
deflector 240 which extends downwardly and outwardly
from the end section 242 of the body.
The conoid shaped body includes a pair of
opposed side walls 244 which at their free end sides,
are in substantially parallel relationship. Each of the
sides 244 has an upper portion 246 arcuately blending
into a top 248 which forms a continuous curved enclosure
for the body. As will be seen from the blade of the
present inventionj each of the blades has a varying
cross-section so that the cross-section taken along the
Z;~
-32-
central portion of the conoid body is of greater cross-
sectional area than the discharge portion (Figure 16C)
and in turn, the cross-sectional area at the end opposed
to the discharge end (Figure 16A) is greater than that
05 in the central portion of the device.
The sides 244 include a further arcuately
shaped margin 250 which in this case, include a pair of
tabs 251 adapted to permit mounting of the blade to an
assembly as described hereinafter. Referring again to
the discharge end, the deflector 240 includes a down-
wardly projecting cowling which otherwise is intended to
deflect the thrust of the wind captured by the blade
from its normal orientation which would otherwise occur
should the deflector not be present. To this end, the
blade of Figures 16A through 16C differs from the blades
previously described by including the deflector 240.
Referring now to Figure 17, a double row of
blades 210 :is mounted to a hollow shaEt 252 which in
turn rotates about a fixed shaft 220 tdescribed pre-
viously) by means of bearing assemblies 254. Bearing
assemblies 254 may be located at spaced-apart points so
as to provlde more than one assembly for rotation of the
shaft 252 about shaft 254. Blades 210, of the type
previously described and which may include the deflector
240 are mounted about the periphery o:E a supporting
member 256; as will be seen from Figure 17, two rows of
blades, one on top of the other, are provided. In order
to facilitate mounting of the blades, the supporting
structure otherwise fixedly secured to the shaft 252,
may~be braced with supporting rods 258 to provide added
strength to the assembly. In this way, the structure
shown in Figure 17 can be utilized for various purposes,
one of which is illustrated in Figure 18 wherein similar
L22~1
-33-
parts are designated by similar reference numerals
rela-tive to -the figures previously described. Thus,
shaft 252 mounts a sprocket 260; a generator or pump 262
is also provided with a sprocket 264 with a chain
05 connecting the two sprockets 260 and 264 so that
rotation of the shaft 252 will drive the generator or
pump member 262. When the member 262 is a pump, it is
connected to a source of e.g. sea water and from there,
the pump is effective to provide a supply of e.g. sea
water through conduit 266 to a reverse osmosis device
268 where the sea water may be desalinated/purified to
provide a source of potable water.
In the above arrangements, the pump 262 may be
mounted to appropriate frame members by suitable means
and the apparatus enclosed within a housing as desired.
Referring now to Figure 19 there is illus-
trated a modified blade design in which there is pro-
vided a closed end portion. In this blade, the conoid
shaped conEigura-tion oE the body indicated generally by
reference numeral 270 includes a pair of generally
parallel side panels 272 which terminate at their upper
end in a concave shaped dome 274 with each side portion
uniformally blending into the dome shaped member. The
lower end portions include a pair of flanges 276 which
are adapted to mount the blades 270 onto a supporting
member in structure similar to e.g., tha-t oE Figure 17.
Such flanges 276 may extend only a portion of the length
of the body.
~s will be seen from Figure 19, the dome
shaped body includes a larger end 278 which has an area
of greater cross-section along the line A - ~ than the
intermedia-te portion 2~0 along the line B - B which in
turn, still has a greater cross-section than the opposed
end 282 along the line C - C.
In the modif~ied version shown in Figur 19,
the blade not only includes a deflecting portion
indicated generally by reference numeral 284 similar to
that of Figure 16 but further deflects the air stream
~0
1~9~l2Zal
-34-
approximately at right-angles to the axial flow within
the body 270. Thus, the conoid shaped body includes, at
one end, a deflector which extends a-t right-angles to
change the direction of air flow within the body. In
05 this arrangement, the sides 270 thus taper from one end
to the other in a reducing cross-section. The upper
dome member also blends into the deflector 284 in a
concave configuration as seen from Figure 22.
From the arrangements described above, it will
be seen that the apparatus of the present invention is
characterized by an increased power output and
efficiency, and is adapted to utilize a maximum of the
available energy carried by low speed "prevalent" winds
while still being capable of operating at higher energy
wind speeds.
The apparatus of the present invention
substantially reduces the possibility of power failures
or the "running away" effect of various conventional
rotors during high wind velocities. The apparatus oE
the present invention is also versatile in that it can
be moun-ted in a horizontal or vertical position and due
to its sensitivity at low wind velocities and its high
eficiency, can be installed at ground level or
close to ground level thus reducing the cost of
installation and maintenance.
Still further, relatively inexpensive rotor
and blade materials can be employed and air flow inlet
concentrators may be used to direct an air stream into
the centre of a rotor disc. Such an arrangement will
still further improve the efEiciency of power conversion
as it will shield the rotor blades from cutting into an
incoming wind stream. The frontal shield and in that
concentrator can be part of the apparatus attached to
and rotating with it or, can be mounted as a separate
unit by suitable supports.
:: :
~29~220
-35-
Preferablyt if an elbow is employed as a "air
scoop", it is mounted on a centrally located shaft
serving as a pivot and desirably, a wind vane is
attached to the scoop to provide means for keeping the
05 air inlet perpendicular to the oncoming wind. As
indicated, a shroud may be employed to extend over the
frontal and outside area of a rotor, again protecting
its blades from turning back into a flowing wind-stream
and also acting as a rotor protector against any wind
borne objects. It may also be used as a means of
protecting an operator. If desired, the air scoop may
be mounted at elevations above the unit to collect winds
with higher velocities where a turbine is installed at
ground level. Preferably the concentrator elbow is
rotatably mounted on a common shaft with the apparatus
or alternately, other conventional rotary guide ar-
rangements may be employed to facilitate its pivotal
movement to respond to different wind directions~ Still
further, the concentrator elbow may be constructed so as
to collapse at high wind speeds for protection against
damage to the disc and blades caused by drag pressure
forces, or against heavy rain or snowfall. As
illustrated in the drawings, the apparatus of the
present invention may also be constructed with two or
more sets of blades, mounted back-to~back, for an
increase in power production. In this arrangement, a
larger air scoop area will have to be provided, e.g.,
double the typical single blade arrangement, to increase
the quantity kinetic energy entering the turbine. The
rotor or disc does not, however r have to be increased in
diameter to recover efficiently the amount of energy
contained in the increased air volume. Thus, unlike
present day rotors, the apparatus of the present
invention can increase its power output using
standardized elements for the runner disc and its blades
and thus offer more inexpensive units, simpler
construction and more economical wind-extracting
systems.
lZ~22~
-36-
In practicing the invention, the various
components of the turbine assembly, and the blade per
se, can be manufactured of suitable material suitable
for the purpose intended. Thus, for example, the blades
05 and associated components can be made of material such
as rigid or semi-rigid plastic materials, sheet metals
such as sheet aluminum, etc.
It will be understood that various modifi-
cations can be made to the above described embodiments
without departing from the spirit and scope o~ the
invention.
