HK1162637A - Inflatable wind turbine - Google Patents

Abstract

A wind turbine has an impeller surrounded by a turbine shroud and/or an ejector shroud, wherein the turbine shroud and/or the ejector shroud include inflatable portions and/or flexible inflatable portions. In some embodiments, the turbine shroud and/or the ejector shroud include internal rib members whose shape or length can be changed to alter the characteristics of the wind turbine.

Description

Expandable wind turbine

Cross Reference to Related Applications

This application claims priority from U.S. provisional patent No.61/191358 filed on 8/9/2008. The entire contents of this provisional application are incorporated herein by reference.

Technical Field

The present invention relates to wind turbines, and in particular to systems using inflatable members.

Background

Conventional wind turbines for power generation typically have 2-5 open blades arranged in a propeller-like configuration, mounted on a horizontal shaft connected to a gearbox that drives a generator. Such turbines are commonly referred to as horizontal axis wind turbines or HAWTs. Although HAWTs have been widely used, their efficiency is not optimal. Specifically, the efficiency does not exceed the betz limit of 59.3% in extracting potential energy from the wind passing through the turbine.

Conventional wind turbines have three blades and are oriented or pointed into the wind by a motor controlled by a computer. These turbines typically require support towers 60 to 90 meters high. The blades typically rotate at a speed of about 10 to 22 revolutions per minute. Although in some designs the ring generator may be directly driven, a gearbox is typically utilized to step up the speed of the drive engine. Some turbines operate at a constant speed. However, more energy can be harvested by employing a variable speed turbine and a solid state energy converter that engages the turbine with a generator.

There are problems with the construction and operation of HAWTs. It is difficult to transport tall towers and long blades. A large tower structure is required to support the heavy blades, gearbox and generator. The equipment needs to be equipped with very high and expensive cranes and skilled operators. In operation, the HAWT requires an additional yaw control mechanism to turn the blades into the wind. HAWTs typically have a large angle impact on the wing that does not provide variable variation to the wing in the wind flow. HAWTs are difficult to operate near the ground or in turbulent winds. Ice build-up on the engine compartment and blades can lead to reduced power and safety issues. High HAWTs may affect airport radar. This height also makes the HAWT obtrusively visible in large areas, spoiling the appearance of a landscape and sometimes objectionable to local people. Finally, downwind variants (downwind variants) suffer from fatigue and structural damage due to turbulence.

It is desirable to reduce the weight and size of wind turbines.

Disclosure of Invention

The invention describes a wind turbine with reduced weight and size. Specifically, the wind turbine includes a nacelle and/or a jet having an inflatable member. Such a wind turbine is lighter. The expanded shroud and/or ejector allows the turbine to change its aerodynamic shape to accommodate changes in fluid flow. It also allows for less firm support of the turbine body and it also allows the expanded section to be collapsed and stored under the demands of severe weather conditions. The expansion portion of the turbine does not actively rotate to assist in energy extraction or power generation.

An embodiment discloses a wind turbine, comprising: an impeller; and a turbine shroud disposed about the impeller, the turbine shroud including an expandable member. The expandable member may have the shape of an annular wing.

The turbine shroud may also include a first rigid structural member coupled to the inflatable member. The housing first rigid structural member may include a hollow interior into which the housing inflatable member is insertable. In some embodiments, the nacelle first rigid structural member defines a leading edge of the turbine nacelle.

The turbine shroud may also include a second rigid structural member coupled to the shroud inflatable member opposite the shroud first rigid structural member, wherein the second rigid structural member defines a trailing edge of the turbine shroud.

The nacelle second rigid structural member may be formed to provide a plurality of lobes to the turbine nacelle. Alternatively, the shroud inflatable member is formed to provide a plurality of lobes around a trailing edge of the turbine shroud.

The wind turbine may further comprise an ejector shroud arranged coaxially around the turbine shroud, the ejector shroud comprising an inflatable member. The ejector shroud may further comprise a first rigid structural member connected to the ejector inflatable member. Also, the injector first rigid structural member may include a hollow interior into which the injector expandable member is insertable. The injector first rigid structural member may also define a leading edge of the injector housing.

The injector shroud may further include a second rigid structural member connected to the injector inflatable member opposite the injector first rigid structural member, the second rigid structural member defining a trailing edge of the injector shroud. The ejector second rigid structural member may be formed to provide the ejector shroud with a plurality of lobes.

The injector expandable member is configured such that when the injector expandable member is partially expanded, an area defined by a trailing edge of the injector expandable member is less than an area defined by a leading edge of the injector expandable member. The ejector inflatable member may also be formed to provide a plurality of lobes around a trailing edge of the ejector shroud.

Other embodiments disclose a wind turbine comprising: a turbine shroud; and an ejector shroud disposed coaxially around the turbine shroud; the turbine shroud includes a shroud circular member, a plurality of shroud first rib members engaged with the shroud circular member, and a shroud outer membrane, wherein the shroud circular member and the plurality of shroud first rib members define an intake end and an exhaust end of the turbine shroud; and the injector housing includes an injector circular member, a plurality of injector first rib members engaged with the injector circular member, and an injector outer membrane, wherein the injector circular member and the plurality of injector first rib members define an intake end and an exhaust end of the injector housing.

The turbine shroud may further include a plurality of shroud second rib members. Each shroud second rib member extends between the shroud circular member and the injector circular member. The plurality of shroud first rib members and the plurality of shroud second rib members together define a plurality of mixer lobes at an exhaust end of the turbine shroud.

The injector shroud may further include a plurality of injector second rib members engaged with the injector circular member. The plurality of injector first rib members and the plurality of injector second rib members together define a plurality of mixer lobes at the exhaust end of the injector housing.

The injector first rib member may include a fixed member and an actuating member connected together at a pivot to change an angle between the fixed member and the actuating member.

Alternatively, the injector first rib member may comprise a fixing member and an actuating member, the fixing member and the actuating member being joined together to enable the length of the injector first rib member to be varied.

Also disclosed is a wind turbine comprising: an impeller; a turbine shroud disposed about the impeller and having a plurality of mixing lobes disposed about an exhaust end; and an ejector shroud, the ejector disposed about the turbine shroud, the ejector shroud including an expandable member.

These and other non-limiting features or characteristics of the present invention will be further described below.

Drawings

The following is a brief description of the drawings, which are intended to illustrate the enumerated disclosure and should not be taken as limiting the disclosure.

Fig. 1 is a perspective view of a first exemplary embodiment of the present invention.

Fig. 2 is a perspective view of a second exemplary embodiment of the present invention.

Fig. 3 is a perspective view of a third exemplary embodiment of the present invention.

Fig. 4 is a perspective view of a fourth exemplary embodiment of the present invention.

Fig. 5 is a partial perspective view of a fifth exemplary embodiment of the present invention.

Fig. 6A is a side view of a sixth exemplary embodiment of the present invention.

Fig. 6B is a perspective view of a sixth exemplary embodiment of the present invention.

Fig. 7A to 7D are perspective views illustrating various stages of a construction process of other exemplary embodiments of the present invention.

Fig. 8A-8C are side views of various internal rib features that may be used with exemplary embodiments of the present invention.

Fig. 8D to 8E show the wind turbine before and after use of various internal rib components such as those shown in fig. 8A to 8C.

Fig. 9 is a perspective view of an eighth exemplary embodiment of the present invention.

Fig. 10 is a perspective view of a ninth exemplary embodiment of the present invention.

Detailed Description

The disclosed processes and apparatuses may be more completely understood with reference to the accompanying drawings. The drawings are merely schematic representations based on convenience and the convenience of demonstrating the prior art and/or the present invention, and are, therefore, not intended to indicate the relative sizes and dimensions of the components or parts thereof.

Although specific terms are used in the following description for the sake of clarity, these terms are used only to refer to the particular structure of the embodiments selected for illustration in the drawings, and are not intended to define or limit the scope of the disclosure. In the drawings and the following description, it is to be understood that like reference numerals refer to parts that perform like functions.

In general, the invention includes a wind turbine including an inflatable member. The invention provides a wind turbine having a weight less than the weight of a HAWT.

Fig. 1 is a perspective view of a first embodiment of the inventive wind turbine, also referred to as mixer-ejector wind turbine (MEWT). The MEWT is a new type of wind turbine that uses shrouded wheels, supports, or rotors/stators to increase the efficiency of the wind turbine so that more power can be extracted in the same area as compared to other existing types of wind turbines. The MEWT accomplishes this by drawing air from a larger area than the most common type of wind turbine, the Horizontal Axis Wind Turbine (HAWT).

The wind turbine can theoretically obtain 59.3% of the potential energy of the wind passing through the wind turbine at maximum, which is called the betz limit. The amount of energy harvested by a wind turbine may also be referred to as the efficiency of the turbine. MEWT can exceed the betz limit.

Referring to FIG. 1, a turbine 10 includes an impeller 20 located at an inlet end 32 of a turbine shroud 30. The impeller may generally be any of the following: the blades are connected to a shaft and are rotatable, and the impeller is capable of generating electrical energy or energy from the wind that rotates the blades. As shown, the impeller 20 is a rotor-stator assembly. The stator 22 is engaged with the turbine housing 30, and the rotor (not shown) is engaged with the motor/generator (not shown). The stator 22 has non-rotating blades 24 that deflect the air before it reaches the rotor. Then, the blades of the rotor rotate, thereby generating electric power in the generator. The nacelle 30 includes an annular airfoil 34, in other words, the nacelle 30 is generally cylindrical and has an airfoil shape configured to generate a relatively low pressure within the turbine nacelle (i.e., inside the nacelle) and a relatively high pressure outside the turbine nacelle (i.e., outside the nacelle). In other words, the annular wing has an aircraft wing-like cross-sectional shape as seen in FIGS. 4, 7, 12, 14, 17 and 19 of U.S. patent publication No.2009/0087308, which is incorporated herein by reference in its entirety. The impeller and the motor/generator are housed within a turbine housing. The turbine shroud 30 may also have a mixer lobe 40 disposed about the outlet or exhaust end of the shroud. The mixer lobes are typically evenly arranged around the circumference of the discharge end. The mixer lobes generally give the exhaust end 36 of the turbine shroud, which discharges air, a substantially wave-trough shape around its circumference. In other words, the petals 40 are disposed along the trailing edge 38 of the shroud.

The turbine 10 also includes an ejector shroud 50 engaged with the turbine shroud. The injector shroud includes an annular vane 54, in other words, the injector shroud is generally cylindrical and has the shape of a vane configured to generate a relatively high pressure within the injector (i.e., between the turbine shroud 30 and the injector shroud 50) and a relatively low pressure outside the injector shroud 50. The ejector shroud may also have mixer lobes 60, in which case the wind turbine is a mixer-ejector wind turbine. The mixer lobes generally give the air-discharging exhaust end of the ejector 56 a substantially wave-valley shape around its circumference. In other words, the mixer lobes are disposed along the trailing edge 58 of the ejector shroud 50.

The ejector shroud 50 has a diameter greater than the diameter of the turbine shroud 30. The turbine shroud 30 is engaged with the ejector shroud 50. In other words, the exhaust end 36 of the turbine shroud fits within the intake end 52 of the injector shroud, or the intake end 52 of the injector shroud surrounds the exhaust end 36 of the turbine shroud. The turbine shroud 30 and the ejector shroud 50 are sized to allow air to flow therebetween. In other words, the ejector shroud 50 is coaxially disposed around the turbine shroud 30, and is disposed downstream of the shroud 30. The impeller 20, the turbine shroud 30 and the ejector shroud 50 together share the same axis, i.e. are coaxial with one another.

The mixer lobes 40, 60 allow for advanced fluid mixing and control. Turbine shrouds and ejector shrouds differ from similar shapes used in the aircraft industry because, in MEWT, the flow path provides high energy air to the interior of the ejector shroud. The turbine shroud provides low energy air to the ejector shroud interior, and the high energy air surrounds, draws and mixes with the low energy air outwardly.

As the wind drives the rotor, the motor/generator may be utilized to generate electricity. The generator on the turbine may also act as a motor driving the impeller 20, drawing air in and through the turbine 10 when the wind is insufficient to drive the rotor.

With continued reference to FIG. 1, the turbine shroud 30 includes an expandable member 70, a first rigid structural member 72, and a second rigid structural member 74. The first rigid member defines a leading edge 76 of the nacelle 30 and the second rigid member 74 defines a trailing edge 38 around which the plurality of petals 40 are wrapped. The rigid members 72, 74 are connected to the expandable member 70 opposite one another, i.e., to opposite sides of the expandable member. The first rigid structural member 72 is annular. The first rigid structural member 72 provides the structure that supports the impeller 20 and also acts as a funnel for directing air through the impeller. The expandable member 70 is made of a film material which will be described later. The rigid members 72, 74 may be flexible and considered rigid relative to the expandable member 70.

The injector shield 50 also includes an expandable member 80, a first rigid structural member 82, and a second rigid structural member 84. The first rigid member defines a leading edge 86 of the injector 50 and the second rigid member 84 defines a trailing edge 58 around which the plurality of petals 60 are wrapped. The rigid members 82, 84 are connected to the expandable member 80 opposite one another, i.e., to opposite sides of the expandable member. Likewise, the rigid members 82, 84 may be flexible and considered rigid relative to the expandable member 80. The expandable members 70, 80 may comprise one large bag capable of expansion, or may comprise multiple bags capable of independent expansion/contraction.

FIG. 2 illustrates another exemplary embodiment of a turbine. The turbine 110 has a wheel 120, a turbine shroud 130, and an ejector shroud 150. In this embodiment, the turbine shroud 130 includes a first rigid structural member 132 coupled to an inflatable member 134. The first rigid member 132 defines a leading edge 136 of the outer shroud 130. The shroud inflatable member 134 is formed having a plurality of lobes 140 disposed about the trailing edge 138 of the turbine shroud. Unlike the embodiment of fig. 1, there is only one rigid member connected to the inflatable member. Similarly, the injector 150 includes a first rigid structural member 152 connected with an inflatable member 154. The first rigid member 152 defines a leading edge 156 of the injector housing 150. The ejector inflatable member 154 is formed with a plurality of petals 160 disposed about the trailing edge 158 of the ejector shroud. In other words, in the present embodiment, there are no rigid components defining the lobes on the expandable turbine shroud 130 and/or the expandable ejector shroud 150.

FIG. 3 illustrates another exemplary embodiment of a turbine. The turbine 110 has a wheel 120, a turbine shroud 130, and an ejector shroud 150. In the present embodiment, the turbine shroud 130 includes an expandable member, and the ejector shroud 150 includes an expandable member. In other words, there are no rigid structural members at either the leading or trailing edges of the turbine shroud or the ejector shroud.

Fig. 4 shows another exemplary embodiment. Here, turbine shroud 130 and ejector shroud 150 are formed from an expandable material and form a subassembly configured to retrofit an existing turbine or propulsion device.

Fig. 5 shows another exemplary embodiment of the present invention. Here, turbomachine 200 has an impeller 210, a turbomachine casing 220, and an injector casing 230. Impeller 210 is a rotor-stator assembly. The stator 212 has a plurality of blades 214. The turbine shroud 220 includes a rigid structural member 222 surrounding the stator 212, the rigid structural member 222 having a substantially circular shape and defining a leading edge of the turbine shroud. Similarly, the injector shroud 230 includes a rigid structural member 232, the rigid structural member 232 having a substantially circular shape and defining a leading edge of the injector shroud. The housing rigid member 222 and the injector rigid member 232 are connected together by a strut 224. The turbine shroud 220 also includes an expandable member (not shown), and the injector shroud 230 also includes an expandable member 234. In this embodiment, the inflatable member is designed to deflate and compress to change the shape of the turbine for protection in high wind speed environments or ice storms. The housing rigid structural member 222 includes a hollow interior into which the expandable member can be pulled. It should be appreciated that in these figures, the hollow interior is located at the trailing edge 226 of the nacelle rigid member 222 and is not visible. There is shown a turbine shroud 220 having its expandable member fully compressed and stored within a shroud rigid member 222. Similarly, the injector expandable member 234 may also be collapsed and stored within the hollow interior of the injector rigid structural member 232.

Fig. 6A and 6B are two views of another exemplary embodiment. Likewise, turbomachine 300 includes a turbomachine nacelle 310 and an injector nacelle 320. The turbine shroud includes a rigid structural member 312 and an expandable member 314, shown here in a fully expanded state. The ejector shroud also includes a rigid structural member 322 and an expandable member 324. Here, however, the injector expandable member 324 has sufficient flexibility so that it can exhibit different forms or shapes according to the degree of expansion. Here, the expandable member 324 is shown only partially expanded, such that the area of the discharge end 326 is reduced. As shown, the reduced area will compress the airflow through the turbine, reducing the airflow and thus any stress that may be generated on the impeller or rotor-stator assembly in high wind speed environments. In other words, the injector inflatable member 324 is configured to: in the partially expanded condition, the area 330 bounded by the trailing edge 332 of the injector expandable member is less than the area bounded by the leading edge 334 of the injector shroud. Note that the area bounded by the leading edge refers to the entire area defined by the leading edge, and not just the annular area between the turbine shroud 310 and the ejector shroud 320.

7A-7C illustrate various stages of construction of other exemplary embodiments of shrouds and/or ejectors for wind turbines of the present invention. The impeller is not shown in these figures. Here, shroud/injector combination 390 includes a circular member 400 and a plurality of shroud first rib members 410, where circular member 400 and plurality of shroud first rib members 410 collectively define an intake end 402 and an exhaust end 404 of the turbine shroud. The circular member 400 and the plurality of shroud first rib members 410 are then covered with an outer film material 406 to complete the turbine shroud. The exhaust end 404 of the turbine shroud may have a smaller area than the intake end 402. Similarly, the injector housing includes a circular member 420 and a plurality of injector first rib members 430, the circular member 420 and the plurality of injector first rib members 430 collectively defining an intake end 422 and an exhaust end 424 of the injector housing. Then, the circular member 420 and the plurality of injector first rib members 430 are covered with an outer film material 426 to complete the injector housing. In some embodiments, the shroud circular member 400 and the injector circular member 420 are connected to each other by a shroud first rib member 410.

In other embodiments, the turbine shroud may include a plurality of shroud second rib members 440. The shroud second rib member 440 connects the shroud circular member 400 and the injector circular member 420. Nacelle first rib member 410 and nacelle second rib member 440 collectively define a plurality of mixer lobes 442 located at nacelle discharge end 404. Generally, the housing first rib member 410 and the housing second rib member 440 have different shapes. Similarly, in other embodiments, the injector shield may include a plurality of injector second rib members 450. Injector first rib element 430 and injector second rib element 450 collectively define a plurality of mixer lobes 452 located at exhaust end 424 of the injector. Generally, the injector first rib part 430 and the injector second rib part 450 have different shapes.

As shown in fig. 7A, the housing first rib member 410 and the injector first rib member 430 are connected to the injector circular member 420 at the same position. Similarly, the shroud second rib member 440 and the injector second rib member 450 are connected to the injector circular member 420 at the same position. It is not necessary that the rib members be connected at the same location.

Alternatively, as shown in FIG. 7D, the shroud/injector combination 390 may be considered to include a first circular component 400, a second circular component 420, a plurality of first internal ribs 460, and a plurality of second internal ribs 470. The combination of the two circular members, the first internal rib and the second internal rib define the shape of the turbine shroud, the lobes on the turbine shroud, the ejector shroud and the lobes on the ejector shroud. The turbine shroud is defined by the area between the two circular members 400 and 420, while the injector shroud is disposed downstream of the second circular member 420. In contrast to fig. 7A, the first internal rib 460 may be considered as an integral combination of the shroud first rib member 410 and the injector first rib member 430, while the second internal rib 470 may be considered as an integral combination of the shroud second rib member 440 and the injector second rib member 450.

Fig. 8A-8C are side views of various embodiments of internal ribs suitable for use with the various embodiments shown in fig. 7A-7C. In fig. 8A, the rib 500 includes an arcuate member 510 and a transverse member 520 integrally formed to together form a generally rigid rib. These components are generally lightweight and may be considered beams 502 connected together by struts 504. The arched member 510 defines the shape of the turbine shroud, while the cross member 520 defines the shape of the ejector shroud.

Referring to fig. 8B, the rib 500 includes a fixing part 530 and an actuating part 540. The stationary part 530 defines the shape of the turbine shroud, while the actuating part 540 defines the shape of the ejector shroud. The fixed member 530 and the actuating member 540 are coupled together along the bottom edge 508 by a pivot 550 that defines an angle therebetween. The fixed member 530 and the actuating member 540 are coupled together along the top edge 506 by a sleeve or linear moving member 560. The actuator 570 engages both the stationary member 530 and the actuating member 540 to change the angle therebetween, thereby changing the shape of the shroud and/or the injector. The solid lines show the shortened or straight position and the dashed lines show the extended or inclined position. This ability to change shape allows the entire frame of the turbine shroud or the ejector shroud to also change/change shape.

Referring to fig. 8C, the fixing member 530 and the actuating member 540 are connected together at both the top edge 506 and the bottom edge 508 by a sleeve or linearly moving member 560, and the sleeve or linearly moving member 560 changes the length of the rib 500 together with the actuator 570.

Fig. 8D shows a turbine 580 having a turbine shroud 582 and an ejector shroud 584. Here the rib member of the injector (not shown) is in a shortened position. In fig. 8E, the rib member of the ejector shroud is in an extended position, resulting in an ejector with a greater length and different air flow characteristics. Thus, the flexible nature of the rib members in a wind turbine allows the wind turbine to be reconfigured to accommodate different wind conditions.

In FIG. 9, a wind turbine 600 has an impeller shown as a propeller 602 mounted on a motor 604 and supported on a post 606. An inflatable enclosure 608 is provided around the propeller 602. Thus, the inflatable nacelle may be applied to existing types of wind turbines.

FIG. 10 is an alternative embodiment in which turbine 600 is not supported by a column. Instead, the expandable enclosure 608 has been expanded with a lighter-than-air gas, such as hydrogen, helium, ammonia, or methane. This provides sufficient buoyancy for the free rise of the turbine 600. The turbine 600 is tethered by a tether or rope 610 that is connected to a controller that can lengthen or shorten the tether 610. Thus, no support structure other than the tether 610 is required. The base 612 may include a spool or reel for controlling the length of the tether 610. Such a feature may provide a simple, fast response means of lowering the turbine 600 in the event of excessive wind speeds.

The expandable member described herein may include several lumens for controlling the amount of lift or degree of expansion. Suitably, the lumens may be arranged around the circumference of the expandable member or from one end of the expandable member to the other.

The film material used to form the outer cover and/or inflatable member of the eductor and the outer membrane may be made from essentially any polymeric or fabric material. Typical materials include multilayer films of polyurethane, polyfluoropolymer, and the like. Stretchable fabrics such as spandex-type fabrics may also be used.

Polyurethane films are strong and have good weatherability. Polyester polyurethane films are more sensitive to a decrease in hydrophilicity (hydrophilic degradation) than polyether polyurethanes. The aliphatic versions (aliphatic versions) of these polyurethane films also typically have uv resistance.

Typical polyfluoropolymers include polyvinylidene fluoride (PVDF) and polyvinyl fluoride (PVF). Commercially available forms are KYNAR and TEDLAR. Polyfluoropolymers typically have very low surface energies, which makes them somewhat dirt-free, debris-free, and easier to de-ice than materials with higher surface energies.

It is also contemplated to make the inflatable member or outer membrane from a membrane/fabric composite along with a padding such as foam.

The inflatable member may also be constructed of a urethane film bladder with a woven or braided cover that enhances its strength and durability. The woven or braided material may be polyester, pre-stressed polyester, polyarylate (trade name: VECTRAN)Manufactured by Kuraray of japan), p-phenylene terephthalamide (PpPTA) (trade name: TWARON, manufactured by Akzo), PPTA (poly-paraphenylene terephthalamide) (trade name: KEVLAR, manufactured by DuPont), and polytrimethylene terephthalate (trade name: CORTERRA, manufactured by Shell). The woven or braided cover may be coated with various polymers, such as cis-polyisoprene, polyurethane, epoxy, or polyvinyl chloride. This protects the woven or knitted fabric from environmental attack such as ultraviolet light, or abrasion from sand or other materials that may damage the fabric. The manufacturers include: federal Fabrics-Fibers of Lowell, MA; warwick Mills of New Ipswich, NH; vertigo lnc of Lake Elsinore, CA; and ILC Dover of Frederica, DE. The expandable member may also be partially or fully reinforced by using a reactive polymer infusion process, using Vacuum Assisted Resin Transfer Moulding (VARTM) or curing of a pre-infused polymer such as unsaturated polyester, epoxy, acrylate or urethane by radiation, free radical initiation or isocyanate crosslinking.

The expandable configuration of the nacelle and/or the ejector of the wind turbine of the present invention makes the turbine of the present invention significantly lighter than conventional turbines. Thus, a support tower having low solidity can be used.

The system and method of the present invention have been described with reference to exemplary embodiments. Obviously, modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the exemplary embodiment be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

Claims (22)

1. A wind turbine, comprising:

an impeller; and

a turbine shroud disposed about the impeller, the turbine shroud including an expandable member.

2. The wind turbine of claim 1, wherein the turbine nacelle further comprises a first rigid structural member connected to the inflatable member.

3. The wind turbine of claim 2, wherein the nacelle first rigid structural member includes a hollow interior into which the nacelle inflatable member is insertable.

4. The wind turbine of claim 2, wherein the nacelle first rigid structural member defines a leading edge of the turbine nacelle.

5. The wind turbine of claim 2, wherein the turbine nacelle further comprises a second rigid structural member connected to the nacelle inflatable member opposite the nacelle first rigid structural member, the second rigid structural member defining a trailing edge of the turbine nacelle.

6. The wind turbine of claim 5, wherein the nacelle second rigid structural member is formed to provide the turbine nacelle with a plurality of mixing lobes.

7. The wind turbine of claim 1, wherein the shroud inflatable member is formed to provide a plurality of mixing lobes around a trailing edge of the turbine shroud.

8. The wind turbine of claim 1, further comprising an ejector shroud disposed coaxially around the turbine shroud, and the ejector shroud includes an inflatable member.

9. The wind turbine of claim 8, wherein the ejector shroud further comprises a first rigid structural member connected to the ejector inflatable member.

10. The wind turbine of claim 9, wherein the ejector first rigid structural member comprises a hollow interior into which the ejector inflatable member is insertable.

11. The wind turbine of claim 9, wherein the ejector first rigid structural member defines a leading edge of the ejector shroud.

12. The wind turbine of claim 9, wherein the ejector shroud further comprises a second rigid structural member connected to the ejector inflatable member opposite the ejector first rigid structural member, the second rigid structural member defining a trailing edge of the ejector shroud.

13. The wind turbine of claim 12, wherein the ejector second rigid structural member is formed to provide the ejector shroud with a plurality of mixing lobes.

14. The wind turbine of claim 8, wherein the ejector inflatable member is configured such that when the ejector inflatable member is partially inflated, an area bounded by a trailing edge of the ejector inflatable member is less than an area bounded by a leading edge of the ejector inflatable member.

15. The wind turbine of claim 8, wherein the ejector inflatable member is formed to provide a plurality of mixing lobes around a trailing edge of the ejector shroud.

16. The wind turbine of claim 1, wherein the inflatable member has the shape of an annular wing.

17. A wind turbine, comprising:

a turbine shroud; and

an ejector shroud disposed coaxially around the turbine shroud;

the turbine shroud includes a shroud circular member, a plurality of shroud first rib members engaged with the shroud circular member, and a shroud outer membrane, wherein the shroud circular member and the plurality of shroud first rib members define an intake end and an exhaust end of the turbine shroud; and is

The injector housing includes an injector circular member, a plurality of injector first rib members engaged with the injector circular member, and an injector outer membrane, the injector circular member and the plurality of injector first rib members defining an intake end and an exhaust end of the injector housing.

18. The wind turbine of claim 17, wherein the turbine shroud further comprises a plurality of shroud second rib members, each shroud second rib member extending between the shroud circular member and the ejector circular member; and is

The plurality of shroud first rib members and the plurality of shroud second rib members together define a plurality of mixer lobes at an exhaust end of the turbine shroud.

19. The wind turbine of claim 17, wherein the ejector shroud further comprises a plurality of ejector second rib members engaged with the ejector circular member; and is

The plurality of injector first rib members and the plurality of injector second rib members together define a plurality of mixer lobes at the exhaust end of the injector housing.

20. The wind turbine of claim 17, wherein the ejector first rib member includes a stationary member and an actuating member, the stationary member and the actuating member being connected together at a pivot to change an angle between the stationary member and the actuating member.

21. The wind turbine of claim 17, wherein the ejector first rib member includes a fixed member and an actuating member, the fixed member and the actuating member being joined together to enable the length of the ejector first rib member to be varied.

22. A wind turbine, comprising:

an impeller;

a turbine shroud disposed about the impeller and having a plurality of mixing lobes disposed about an exhaust end; and

an ejector shroud, the ejector disposed about the turbine shroud, the ejector shroud including an expandable member.