CA2103309A1 - Wind turbine assembly - Google Patents

Abstract

ABSTRACT
There is disclosed a wind turbine having an improved turbine wind receptacle for utilizing a maximum of the available energy carried by a low speed wind stream. The improved receptacle structure provides a generally parabolic cross-section and a continuously arcuate interior surface. The parabolic cross-section permits maximum efficient recovery and control of the energy contained in wind streams and accordingly permits the use of the energy for other purposes.

Description

2l03~3013 FIELD OF TI~E INVEIITIO~I
This invention relate~ to an improved wind turbine blade structure. More particularly, this invention is directed to an apparatus which utilizes the kinetic energy of freely flowing masses such as air. The natural energiesi contained in such fluids are infinite and inexhaustible and the present invention provides an assembly which permits the efficient recovery and control of the energies contained in such flow-fields.

BACKGROUND OF l!HE INVENTION
Although the turbine is described in this disclosure as using the 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.

Wind power has been known to humanity for 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 the windfpower 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 disclosure. 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 210330~3 turned to face the wind. The horizontal shaft was turned by the vane. When the mills got too large, they were b~ilt with a revolving turret on top. This turret housed the shaft activated by a rotor and gear box.
They featured big four-bladed rotors, rsctangular in shape, facing the wind.
More recent developments of enti~ely different design have come into use. Water pumping windmills required a high starting torque and to help develop this torque, the rotor became multi-bladed, and was installed on tall towers and utilized a circle of sheet-metal yanes. 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 l! or disturbance from preceding blades and the air-flow 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 ~ph.
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.

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2~.03S30l3 A11 previously descri'oed systems have the a~is of rotation parallel to the direction of the wind.
~ccordingly, in rècent years a number o~ vertical axis rotors have been developed as an alternative source of converting kinetic energy contained in ambient wind strea,n, into shaft rotational energy. These machines have the axis of rotation perpendicula~ to both the surface oE the earth and the wind stream. Vertical-axis rotors 'nave an advantage over 'norizontal-axis units in that they do not have to be turned into the wind. These include the known Savonius, Darrieus, and Cyclo-turbines.
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 adequate to produce power.
; The "Cyclo" turbines (or gyro-mills) have severalvertical blades accepting wind from all direction without orienting to it. It is also self-starting, -however the efficiency is low and the tip-speed ratio is i 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 art of the present wind turbine design is the fact that generally only one rotor can 'oe 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 apparatus 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 of 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 down, and its boundary is an expanding cylinder. The ~ ` `
reduction of wind velocity at the turbine rotor is usual~y expressed as an "interference" factor, "a". The '.~''"''`.,' ;'`'''`~':~
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axial momentum analysis further shows t'nat behind the turbine rotor the interference factor is increased to a value of "2a".
The a~ailable maximum power in a wind current 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 oE 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 'oe expressed in general as P=1/2~ R2SV3. Reduced to atmospheric conditions prevailing at sea level and standard temperature, this formula can be simplified to P=(2.14xlO 6) xV3xA, where "A" is an air inlet (rotor-swept) area, and "V" is wind velocity. However the ~ 9 actual work obtained by existing wind turbines is reduced to P=(2.14x18 6)xAxV3xa(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.
-~ 35 In practice there are some side effects which cause a further reduction in the maximum attainable ~:
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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 mathematical and physical relations existing between power and rotational speed of wind rGtor, and also between torque and rotational speed. sased on actual wind-tunnel tests and on the g~ometric arrangemen-t 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. However, 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 " A" (tip speed ratio).
Power Extracted bY Rotor C = Theoretical Power Contained in Wind Cylinder .. . :. ,. ~ :.: . . .: . :-Rotational Speed of Blade Tip and " ~" = Wind Velocity and the second representing the torque coefficient~
CD = Actual Torque Obtained by Rotor Theoretical Torque and the "Cp and IICD" are related by an expression ~-stating that CD = Cpx ~, 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 vertical rotors, two-bladed and --~
multi-bladed arrangements are shown. One can clearly deduct from these diagrams that the multi-bladed : .: - . .

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_7_ "American" rotor operates at low tip-speed ratio, and two or three-bladed rotors operate at high-tip speed ratios.
Thus, the maximum power coefficient (at 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 maximum torque.
Another significan-t factor is that the multi-bladed "American" rotor, "Savonius" type, and four-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 t~o 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 torque is low and this poses certain limitations on the use of presently built bladed rotors.
It can be appreciated from the above discussions that the wind velocities and therefore their related kinetic energies are the leading factors to be considered while constructing any wind turbine.
It is well known that-in different continents, one can observe that there are well defined groups of ~ wind velocities, which predominate and are called ;~ ~ "prevalent" (frequent) winds. There is also a well defined group of winds which contain the bulk of the energy called "energy" winds. Usually the prevalent winds blow five out of seven days, the energy winds blow two out of seven days tor 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 regulated ~ ' .

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",~ .~ ,,, . - ~-: -2~033~9 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 Erom the winds which blow only 28% of the time.
Considering the foregoing observations and taking into account the operational data, as described hereinafter, of present wind turbines, one can conclude t'nat at the same wind speed and same rotor diameter, a multi-bladed "American" turbine would reach its 2eak operating performance at tip-speed ratio = 1 and the power ratio = 0.3, resulting actually in a low number o~
rotor revolutions. A further increase in tip-speed -;
ratio means an increase in wind velocity and the number of revolutions 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 rotors is more flat, therefore it can accept higher ~ --wind speeds with almost the same power coefficient.
It can be appreciated from the foregoing discussion that little has been accomplished in the present state of art of 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 in a staggered, ~ , 2~ ~33~

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overlapQing 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 pockets to a wind flow.
US 4,522,~00 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 shaft. A wind stream is adapted to enter the narrower front portion and be discharged from the wider outlet, the air being discharged 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 bein~ either of a minor triangular configuration or of a "tab" outline.
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 central 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 arrangement, in which "hook-shaped" projections extend above the plane of the plate in order to catch wind flows.

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2 ~ 3 0 9 US 2,996,120 discloses in Figure 4 parallelogram-shaped blades, partially of a closed structure, in cross-section in which the air flow enters a mouth into the closed parallelogram-5 shaped cross-section forming a 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 portion of the blade.

U.S. 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 15 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 Martin, US 207,189, again no vertical arrangement is possible and no radial wind deflection can be obtained. ;~-8UMMARY OP TH~ INVENTION
one object of the present invention is to provide an improved wind receptacle and wind turbine employing same.

In accordance with a further aspect of this invention, there is provided a turbine wind receptacle suitable for use in a turbine for receiving a flow of air from a wind stream at an inlet portion of the receptacle and deflecting the air via the receptacle to an outlet portion thereof, the improvement wherein:
30 the receptacle comprises a body, the body having a generally parabolic vertical cross-section and a continuously arcuate interior surface extending between the inlet portion and the discharge outlet- -Yet another aspect of the present invention, is to provide 3 ~ 9 a wind turbine comprising: at least one row of wind receptacles, the receptacles having a body, the body having an inlet and an outlet and the body having a generally vertical parabolic cross-section and a continuously arcuate interior surface extendingbetween the inlet and the outlet of the body; frame means for rotatably mounting the at least one row of the receptacles; hood means for deflecting a wind stream into proximity of the receptacles for effecting rotation of the receptacles; and bracing means connecting the frame means and the hood means to brace the at least one row of the receptacles against flexing.

A further aspect of the present invention, is to provide a wind turbine comprising: at least one row of wind receptacles, the receptacles each having a body with an inlet and an outlet, the body having a generally parabolic vertical cross-section and a continuously arcuate interior surface extending between the inlet and the outlet, the wind receptacles being mounted on a support member; frame means for rotatably mounting the support member; and a hood having an inlet and an outlet in fluid communication with the wind receptacles, the hood including reclosable flap means for permitting passage of wind other than through the outlet of the hood.

In one possible embodiment, the turbine will include a triplet of rows of the parabolic bodies, the rows being in a parallel relationship with one another.
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As a further preferred feature, the parabolic bodies in one row are partially nested within one another. This arrangement has an advantage in terms of efficiency with which the bodies can receive the wind stream.

With respect to the interior surface of the parabolic bodies, preferably the same will comprise a smooth continuously " 2~3309 ~

arcuate surface. Such a provision i8 important in terms ~ -permitting smooth flow of the fluid stream to thus realize as much energy as possible.
The use of bracing means has been found effective for substantially reducing flexing of the supports at higher speeds.
Advantageously, the bracing means includes an annular member for receiving the shaft of the turbine. Spokes or ribs radiating -~
from the annular member impart additional support. -~

In addition to the above features, the apparatus will include a power take-off for harnessing the power realized.
Generally, the turbine may be ground mounted or may be elevated by making use of a standard. Numerous possible arrangements of the turbines are contemplated including combinations of rows of turbines, juxtaposed arrangements, or combinations of these.
Arrangement will depend on the particular requirement for the turbine.
Having thus generally described the invention, the above features of the present invention will become more apparent from the following description of the preferred embodiments with reference to the accompanying drawings.
BRIEF DF~CRIPTION OF T~E DR~ING~
Figure 1 is a perspective view of the wind receptacle body;
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Figure 2 is a section on line 1-1 of Figure l;
Figure 3 is a section on line 3-3 of Figure l;

Figure 4 is a rear plan view of the hood assembly;

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21~'~3~39 Figure 5A is a side view of a wind receptacle in one embodiment of the invention;

Figure 5B is a sectional view on line 5B-5B in Figure 5A;

Figure 5C is a sectional view on line 5C-5C in Figure 5A;

Figure 5D is a sectional view on line 5D-5D in Figure 5A;
Figure 5E is an end view of the body;

Figure 6 is a side view illustrating an embodiment of the invention having a plurality of turbines; and Figure 7 is a front view of the structure.

DETAILED DESCRIP~ION OF TH~ PR$FERR~D ~MBODIMENT~

Referring now to Figure 1, shown is a perspective view of an embodiment of the wind turbine assembly, generally denoted by numeral 10.

Generally, the apparatus 10 includes a plurality of bracing members 12 comprising a plurality of elongate rigid members radiating from a central annular ring 14. A similar arrangement is provided on an opposed side of the apparatus. The front and ;j rear bracing members each include, at a terminal end, a connector 16 for receiving auxiliary supports 18. Supports 18 extend between and are connected with a pair of connections 16. In this :~ manner, the bracing members 12 and supports 18 provide an open . framework for protecting the turbine structure discussed h-reinafter.

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The turbine structure has a rotatably mounted telescopic shaft 20, which extends through and is supported by annular rings 14. As illustrated in Figures 1 and 3, at least one end of shaft 20 includes a device 22 suitable for connection with ancillary equipment in order to use energy generated from the rotation of the turbine. As such, the shaft provides a power take-off feature.

Turning to the turbine, generally denoted by numeral 26, the same provides a solid circular frame 28 having a plurality of ribs or spokes 30 radiating from the axis of rotation. Figure 7 generally illustrates the details of this structure. Ribs 30 impart rigidity to circular frame 28 and subsequently reduce flexing during high speed rotation of turbine 26. The ribs 30 are fastened to frame 28. -~

The circular frame 28 has, in spaced parallel relation, a ring 29 concentric therewith. Ring 29 is connected to frame 28 by rods 32 extending diagonally from ring 29. This arrangement is illustrated in Figure 4. Any possible connecting arrangement may be employed for connecting frame 28 with ring 29, provided air flow is possible. ~
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Clearly, several further rings 29 may be connected to one another concentrically. This permits either a singular or a plurality of rows of wind receptacles to be employed, as shown in Figure 6.
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The wind receptacles, shown more clearly in Figures 5A
through 5E, are connected to and extend between, in a first row, frame 28 and ring 29. Additional rows of receptacles are ~ ~-connected between rings 29. ~
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In greater detail, the receptacles 40 each include flanges ' '' ' .'~"
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42 and 44 for connection to either common rings 29 or rings 2 and frame 28. Suitable fasteners facilitate connection.

Each receptacle 40 comprises a hollow open body having a smooth exterior surface 46 and a similar interior surface 48 as illustrated in Figure 5B. Figure 5A illustrates a plan view of a receptacle 40. The shape of receptacle 40, when viewed in plan, generally subscribes to a portion of a semi-circle. The interior surface is preferably smooth and continuously arcuate.
Such a shape has been found to be effective for imparting significant rotation to the turbine even in low velocity wind streams.

Figures 5B through 5E show various sections of the receptacle 40 and, as is clear from Figure 5B, the receptacle has a generally parabolic vertical cross-section with the longitudinal cross-section generally subscribing to a portion of an oblate spheroid.
Figure 5A illustrates the position the receptacle 40 is connected to the ring 30 and frames 28 as discussed herein previously. Accordingly, numeral 50 generally denotes the outlet of the receptacle 40, while 52 refers to the inlet.
Referring briefly to Figure 6, the disposition of a plurality of receptacles 40 is shown. Additional rows are illustrated in phantom.

The turbine can be operated using a single annular "row" of receptacles or with several rows as illustrated in Figure 6.
Within a row, the receptacles 40 are arranged such that the body of one receptacle 40 is partially nested within the outlet 50 of an adjacent receptacle. With respect to the additional rows of receptacles, the rows will be arranged in parallel alignment.

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Extending rearwardly from the turbine and positioned within the framework discussed herein previously, there is provided a hood structure 60. Reference will be made to Figures 1 and 3.
The structure 60 has a solid circular wall 62. A guard wall 61 may be provided in ground level installations to protect turbine 26.

An integral wall 66 provides both sidewalls and a top wall for the hood structure 60. A base wall 70 extends between wall 62 and wall 66.

An inclined front wall 74 extends from wall 62 to proximate base wall 70. A further wall 78 extends from base wall 70 to inclined wall 74. Accordingly, the hood structure 60 has a generally trapezoidal cross-section. The structure 60 generally encloses an internal volume defined by the walls. The circular wall 62 provides an open area 82 which, in turn, communicates with the interior of the turbine. Wall 74, when the assembly 10 is in a use position, faces the fluid stream. The fluid enters the internal volume of hood 60 by opening 84, a flap 86 within wall 74 and hingedly connected thereto at 90. Flap 86 may include lock means for retaining the flap in an open or closed position.
As is evident from the Figures, wall 74 includes a reinforcement member 98 to receive shaft 20. Figure 4 generally illustrates the assembly 10 in cross-section. As is illustrated, a fluid stream, indicated by arrow A passes through opening 84 30 when the flap 86 is open and subsequently into contact with the interior of the turbine. When the stream contacts the inlets 52 of each receptacle 40, the stream induces rotation of the turbine with the subsequent passage of the fluid through the outlets of the receptacles.

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Regarding the shape of the hood structure 60, the generally trapezoidal shape has been found particularly useful for concentrating the fluid stream and has a positive impact on the efficiency of the assembly.

Claims (19)

1. In a turbine blade suitable for use in a turbine for receiving a flow of air from a wind stream at an inlet portion of said blade and deflecting the air via said blade to an outlet portion thereof, the improvement wherein:
said blade comprises a body, said body having a generally parabolic vertical cross-section and a continuously arcuate interior surface extending between said inlet portion and said discharge outlet.

2. The blade as set forth in claim 1 wherein each said blade comprises a hollow body having a parabolic cross-section.

3. The blade as set forth in claim 2, wherein a plurality of bodies are arranged in a partially nested arrangement.

4. The blade as set forth in claim 3, wherein one of said bodies is partially nested within the inlet of a preceding body.

5. The blade as set forth in claim 1, wherein said bodies have a generally oblate spheroid longitudinal cross-section.

6. The blade as set forth in claim 1, wherein at least a portion of said continuously arcuate interior surface comprises a semi-circle.

7. A wind turbine comprising:
at least one row of wind receptacles, said receptacles having a body, said body having an inlet and an outlet and said body having a generally parabolic cross-section and a continuously arcuate interior surface extending between said inlet and said outlet of said body;
frame means for rotatably mounting said at least one row of said receptacles;
hood means for deflecting a wind stream into proximity of said receptacles for effecting rotation of said receptacles; and bracing means connecting said frame means and said hood means to brace said at least one row of said receptacles against flexing.

8. The wind turbine as set forth in claim 7, wherein said hood means includes an inlet and an outlet in fluid communication with said receptacles.

9. The wind turbine as set forth in claim 8, wherein said hood means includes a reclosable flap means for permitting passage of a fluid stream therethrough other than through said outlet of said hood.

10. The wind turbine as set forth in claim 9, wherein said hood means has a generally trapezoidal longitudinal cross section.

11. The wind turbine as set forth in claim 7, wherein said frame means includes a generally circular support member.

12. The wind turbine as set forth in claim 11, wherein said generally circular support includes a plurality radially oriented ribs for supporting said wind receptacles.

13. The wind turbine as set forth in claim 7, wherein said bracing means includes a standard for supporting said receptacles, said standard including mounting means for supporting said at least one row of wind receptacles.

14. A wind turbine comprising:
at least one row of wind receptacles, said receptacles each having a body with an inlet and an outlet, said body having a generally parabolic vertical cross-section and a continuously arcuate interior surface extending between said inlet and said outlet, said wind receptacles being mounted on a support member;
frame means for rotatably mounting said support member; and a hood having an inlet and an outlet in fluid communication with said wind receptacles, said hood including reclosable flap means for permitting passage of wind other than through said outlet of said hood.

15. The wind turbine as set forth in claim 14, wherein said hood has a generally trapezoidal longitudinal cross-section.

16. The wind turbine as set forth in claim 14, wherein said turbine further including bracing means for connecting said frame means and said hood to brace said at least one row of wind receptacles against flexing during high speed rotation.

17. A hood suitable for use with a wind turbine having wind receptacles, said hood comprising a hollow enclosure adapted for positioning in fluid communication with said wind receptacles, said enclosure including moveable flap means for permitting fluid to enter said enclosure;
a fluid outlet in said enclosure for passing said fluid into contact with said wind receptacle whereby said turbine rotates.

18. The hood as set forth in claim 17, wherein said hood includes a generally vertical wall having said outlet and a front wall angularly inclined and diverging relative to said vertical wall.

19. The hood as set forth in claim 17, wherein said enclosure has a generally trapezoidal cross-section.