Rotor blade of a wind turbine comprising a lift modifying device and method for installing thereof

Abstract

A rotor blade of a wind turbine is provided, the rotor blade including a lift modifying device having at least one fluid jet module and at least one compressed fluid source, wherein the at least one fluid jet module includes multiple fluid jets, which are fluidically connected to the at least one compressed fluid source, whereby the at least one fluid jet module is mounted as an add-on onto an outer surface of the suction side or the pressure side of the rotor blade. Also provided is a method for installing this rotor blade, whereby a rotor blade is provided and the at least one fluid jet module is mounted as an add-on onto the outer surface of the suction side or the pressure side of the rotor blade.

Claims

1. A rotor blade of a wind turbine, the rotor blade comprising: a lift modifying device having at least one fluid jet module and at least one compressed fluid source, wherein the at least one fluid jet module is a panel and comprises multiple fluid jets, which are fluidically connected to the at least one compressed fluid source, wherein the panel of the at least one fluid jet module is mounted as an add-on onto an outer surface of a suction side or a pressure side of the rotor blade, the panel of the at least one fluid jet module having a first surface and a second surface opposite of the first surface, the first surface located on the outer surface of the rotor blade, further wherein the first surface and the second surface each having a shape that corresponds to a shape of a portion of the outer surface of the rotor blade to which the at least one fluid jet module is mounted; wherein vortex generators are attached to the second surface of the panel of the at least one fluid module, and, in a chordwise direction, the multiple jets formed by orifices in the panel are located between a leading edge of the rotor blade and the vortex generators; wherein, during a normal operation of the rotor blade, the vortex generators increase a lift coefficient of the rotor blade, and in response to operational or environmental conditions, the lift modifying device is configured to be activated such that the at least one compressed fluid source provides an injection of fluid through the multiple jets which generates a fluid curtain that separates air flow around an airfoil of the rotor blade creating a stalled flow after the multiple jets, which reduces the lift coefficient of the rotor blade and inhibits a vortex generation process of the vortex generators placed after the multiple jets.

2. The rotor blade according to claim 1, wherein the fluid curtain separates the air flow on the suction side or the pressure side of the rotor blade, when the at least one compressed fluid source supplies compressed fluid to the at least one fluid jet module.

3. The rotor blade according to claim 1, wherein the panel has a curved profile defined by a curved outer shape of the second surface.

4. The rotor blade according to claim 1, wherein the at least one fluid jet module is mounted by at least one adhesive, at least one tape, and/or mechanical fasteners onto the outer surface of the rotor blade.

5. The rotor blade according to claim 1, wherein the at least one fluid jet module is mounted reversibly onto the outer surface of the rotor blade.

6. The rotor blade according to claim 1, wherein the at least one fluid jet module is embedded in a recess of a shell of the rotor blade.

7. The rotor blade according to claim 1, wherein the at least one fluid jet module comprises a fluid flow channel fluidically communicating with the multiple fluid jets.

8. The rotor blade according to claim 1, wherein the orifices are fluidically connected to the at least one compressed fluid source.

9. The rotor blade according to claim 1, wherein ramps, spoilers, and/or flaps are attached to the at least one fluid jet module.

10. The rotor blade according to claim 1, wherein at least one fluid supply line fluidically connecting the at least one fluid jet module with the at least one compressed fluid source is at least partially arranged in an inside of the rotor blade, attached to a spar web of the rotor blade.

11. The rotor blade according to claim 10, wherein the at least one fluid supply line is attached externally to the outer surface of the rotor blade and routed to a feed hole inside of a shell of the rotor blade, by which the at least one fluid supply line is fed into the inside of the rotor blade.

12. The rotor blade according to claim 11, wherein the rotor blade comprises at least one structural reinforcement at a location of the feed hole.

13. A method for forming a rotor blade for a wind turbine, the method comprising: providing the rotor blade; and adding at least one fluid jet module onto an outer surface of a suction side or a pressure side to arrive at the rotor blade according to claim 1.

14. The method according to claim 13, wherein a shell of the rotor blade has a recess, into which the at least one fluid jet module is fitted.

15. The rotor blade according to claim 1, wherein the first surface of the at least one fluid jet module achieves a form fit with the outer surface of the rotor blade.

16. The rotor blade according to claim 1, wherein the second surface is located a distance above the outer surface of the rotor blade, the distance corresponding to a thickness of the at least one fluid jet module.

Description

BRIEF DESCRIPTION

(1) Some of the embodiments will be described in detail, with reference to the following figures, wherein like designations denote like members, wherein:

(2) FIG. 1 shows a side perspective view on a rotor blade according to a first embodiment:

(3) FIG. 2 shows a side perspective view on a section of a rotor blade according to a second embodiment;

(4) FIG. 3 shows a side view on the rotor blade of FIG. 1 in operation and with the lift modifying device being deactivated;

(5) FIG. 4 shows a side view on the rotor blade of FIG. 1 in operation and with the lift modifying device being activated;

(6) FIG. 5 shows a sectional cut through a portion of a rotor blade according to a third embodiment;

(7) FIG. 6 shows a side perspective view on a section of a further rotor blade;

(8) FIG. 7 shows a side perspective view on the rotor blade of FIG. 6 equipped with a fluid jet module according to a first embodiment;

(9) FIG. 8 shows a side perspective view on the rotor blade of FIG. 6 equipped with a fluid jet module according to a second embodiment;

(10) FIG. 9 shows a side perspective view on the rotor blade of FIG. 6 equipped with a fluid jet module according to a third embodiment;

(11) FIG. 10 shows a side perspective view on the rotor blade of FIG. 6 equipped with a fluid jet module according to a fourth embodiment;

(12) FIG. 11 shows a side perspective view on yet another rotor blade equipped with a fluid jet module at a first position according to a first embodiment;

(13) FIG. 12 shows a side perspective view on the rotor blade equipped with a fluid jet module at the first position of FIG. 11 according to a second embodiment;

(14) FIG. 13 shows a side perspective view on the rotor blade equipped with a fluid jet module at the first position of FIG. 11 according to a third embodiment:

(15) FIG. 14 shows a side perspective view on a rotor blade equipped with a fluid jet module at a second position; and

(16) FIG. 15 shows a side perspective view on a rotor blade equipped with a fluid jet module at a third position.

DETAILED DESCRIPTION

(17) FIG. 1 shows a side perspective view on a rotor blade 10 according to a first embodiment. The rotor blade 10 comprises a lift modifying device 20.

(18) The lift modifying device 20 comprises a fluid jet module 21. The fluid jet module 21 is mounted as an add-on in the form of a panel onto an outer surface of a suction side 17 of the rotor blade 10. The mounting may be performed by an adhesive, tapes and/or mechanical fasteners. However, none of these are shown here or in the following figures but rather only the state in which the fluid jet module 21 is mounted onto the outer surface of the shell 11 of the rotor blade 10.

(19) The lift modifying device 20 as shown in FIG. 1 is activated and thus generates a fluid curtain A. The fluid jet module 21 is mounted onto the suction side 17 of the rotor blade 10 closer to the leading edge 15 of the rotor blade 10 than to the trailing edge 16 of the rotor blade 10. Further, the fluid jet module 21 is provided closer to the tip of the rotor blade 10 than to its root. However, the fluid jet module 21 may alternatively be placed closer to the trailing edge 16 or the root, if required. Also, alternatively, the fluid jet module 21 may be arranged on a pressure side 18 (see FIG. 15) of the rotor blade 10. The pressure side 18 is located opposite of the suction side 17 at the rotor blade 10. Such further exemplary alternatives of the positioning of the fluid jet module 21 are shown in FIGS. 11 to 15 and will be discussed later with reference thereto.

(20) The fluid jet module 21 is exposed to the outside of the rotor blade 10 while the further components of the lift modifying device 20, namely a fluid supply line 27, a compressed fluid source 22 and a control unit 28, are located inside of the rotor blade 10 in this particular embodiment. However, the control unit 28 may alternatively be located in the hub of the wind turbine, for example. Thus, the fluid supply line 27, compressed fluid source 22 and control unit 28 are drawn with dashed lines. The location of the compressed fluid source 22 and the control unit 28 are only exemplary, these components may also be located inside the wind turbine having the rotor blade 10. Also, the compressed fluid source 22 may be located directly at or close to the fluid jet module 21. The compressed fluid source 22 is configured to provide compressed fluid to the fluid jet module 21 via the fluid supply line 27. Here, the compressed fluid source 22 is a compressor and the fluid is air. However, other fluids may be used and other types of compressed fluid sources 22 may be used.

(21) FIG. 2 shows a side perspective view on a section of a rotor blade 10 according to a second embodiment. In this second embodiment, the lift modifying device 20 comprises two separate fluid jet modules 21.1, 21.2. However, the number of fluid jet modules 21 may be less or more. The fluid jet modules 21.1, 21.2 are mounted as add-ons onto the outer surface of the suction side 17 of the rotor blade 10 and closer to the leading edge 15 than the trailing edge 16. However, the fluid jet modules 21.1, 21.2 may alternatively be arranged closer to the trailing edge 16 than the leading edge 15.

(22) Each of the fluid jet modules 21.1, 21.2 comprises multiple fluid jets 23. The fluid jets 23.1, 23.2, 23.3 of the fluid jet module 21.1 are exemplary denominated. In this case, the fluid jets 23 are provided as orifices within the fluid jet modules 21.1, 21.2. The fluid jets 23 are linearly aligned to generate a substantially straight fluid curtain A as shown in FIG. 1.

(23) Moreover, the fluid jet modules 21.1, 21.2 are arranged at a distance from one another. However, they may alternatively be arranged next to one another.

(24) Each of the fluid jet modules 21.1, 21.2 is fluidically connected via separate fluid supply lines 27.1, 27.2 to the compressed fluid source 22 (not shown in FIG. 2). Alternatively, each of the fluid jet modules 21.1, 21.2 may be connected to a separate one of multiple compressed fluid sources 22 (not depicted in FIG. 2).

(25) Each of the fluid supply lines 27.1, 27.2 has a valve 29.1, 29.2 installed therein. The valves 29.1, 29.2 are connected to the control unit 28 (not shown in FIG. 2). By controlling the valves 29.1, 29.2, the control unit 28 may close or open the separate fluid supply lines 27.1, 27.2 and selectively activate the fluid jet modules 21.1, 21.2. Alternatively, the two valves 29.1, 29.2 may be a three-way-valve 29 and the fluid supply lines 27.1, 27.2 may merge at the three-way-valve 29. Also, when there are more than two fluid jet modules 21.1, 21.2 there may be more fluid supply lines 27 and more valves 29. The hydraulic or pneumatic circuitry of the fluid jet modules 21 with the compressed fluid source 22 depends on the particular installation and there are many possible circuitries for providing selective activation of separate fluid jet modules 21.1, 21.2 by the control unit 28. FIG. 2 merely illustrates an exemplary embodiment for explaining the principles thereof.

(26) The fluid supply lines 27.1, 27.2 are arranged in the inside 12 of the rotor blade 10. They are attached to a spar web 13 of a spar of the rotor blade 10. The spar in this embodiment is of an I-beam type having two spar caps 14.1, 14.2. However, the spar may be also of any other type, such as a box type spar. Also, alternatively, the fluid supply lines 27.1, 27.2 may be attached to an interior side of the shell 11 of the rotor blade 10.

(27) The rotor blade 10 is further provided with multiple vortex generators 30.1, 30.2, 30.3, 30.4, 30.5, 30.6, six of which are exemplary shown and denominated. The vortex generators 30 are attached to the fluid jet modules 21.1, 21.2 of the rotor blade 10 and increase the lift coefficient. The vortex generators 30 may be integrally designed with the fluid jet modules 21.1, 21.2 or attached thereto by mechanical fasteners, tapes and/or adhesive, such that they may easily be serviced and/or replaced.

(28) FIG. 3 shows a side view on the rotor blade 10 of FIG. 1 in operation and with the lift modifying device 20 being deactivated. Here, the air flow W around the airfoil of the rotor blade 10 is not separated by the fluid jet module 21 of the lift modifying device 20. Thereby, the air flow W is an attached air flow W around the airfoil.

(29) FIG. 4 shows a side view on the rotor blade of FIG. 1 in operation and with the lift modifying device 20 being activated. The fluid jet module 21 generates a fluid curtain A or air curtain A and thereby separates the air flow W at the fluid curtain A. The air flow W becomes a separated fluid flow after the fluid jet module 21 and creates a stalled flow. The lift coefficient of the rotor blade 10 is reduced and the drag coefficient of the rotor blade 10 is at the same time increased.

(30) FIG. 5 shows a sectional cut through a portion of a rotor blade 10 according to a third embodiment. Contrary to the rotor blade 10 of FIG. 2, the fluid jet module 21 is embedded in a recess 31 of the shell 11 of the rotor blade 10.

(31) The fluid jet module 21 has a curved outer shape on its outer side 25 to correspond to the shape of the shell 11 of the rotor blade 10. The inner side 26 corresponds in form to a recessed shape of a recess 31 inside of the shell 11 of the rotor blade 10 for form-fitting therewith. The fluid jet module 21 has an elongate body comprising a fluid flow channel 24 fluidically connected to the compressed fluid source 22 and the fluid jets 23.

(32) FIG. 6 shows a side perspective view on a portion of a rotor blade 10 with its shell 11.

(33) FIG. 7 shows a portion of a fluid jet module 21 in the form of a panel mounted as an add-on onto the outer surface of the suction side 17 of the shell 11 of the rotor blade 10 of FIG. 6. The fluid jet module 21 in this particular embodiment has multiple fluid jet modules 21 (only one is denominated in this and the following FIGS. 8 to 10) provided as orifices in the fluid jet module 21 and further multiple vortex generators 30 (only one denominated). The fluid jet module 21 formed as the panel has a substantially flat shape with two large opposite surfaces.

(34) FIG. 8 shows an alternative fluid jet module 21 mounted onto the outer surface of the suction side 17 of the shell 11 of the rotor blade 10 of FIG. 6. This fluid jet module 21 only comprises the multiple fluid jets 23. Further, the fluid jet module 21 is embedded into a recess 31 inside of the shell 11 of the rotor blade 10 and mounted thereto.

(35) FIG. 9 shows the rotor blade 10 of FIG. 7 with the difference that the fluid jet module 21 only comprises the multiple fluid jets 23. Such fluid jet module 21 may be mounted as an add-on on a used rotor blade 10 without having to make any structural changes to the rotor blade 10.

(36) FIG. 10 shows an enlarged portion of the rotor blade 10 of FIG. 9, which shows the fluid jet module 21 in its entire length and with the fluid supply line 27 attached externally to the shell 11 of the wind turbine 10 and running in the chordwise direction of the rotor blade 10 to the trailing edge 16 of the rotor blade 10.

(37) FIG. 11 shows a rotor blade 10 in its full span. A rectangular shaped fluid jet module 21 is mounted as an add-on onto the suction side 17 of the rotor blade 10 and is located roughly at half span on the suction side 17. The fluid supply line 27 is routed in chordwise direction from the fluid jet module 21 to a location between the fluid jet module 21 and the trailing edge 16 of the rotor blade 10. In this location, the fluid supply line 27 is fed through the outer surface or shell 11 of the rotor blade 10 to the inside 12 of the rotor blade 10. For feeding the fluid supply line 27 into the inside 12, a feed hole 32 is provided in the outer surface or shell 11 of the rotor blade 10. Once inside the rotor blade 10, the fluid supply line 27 is routed along the spar web 13 of the rotor blade 10, as shown in FIG. 2, or along the upper or lower or trailing edge surface of the inside 12 of the rotor blade 10. Alternatively, it may be guided along precasted channels inside the structure of the rotor blade 10.

(38) FIG. 12 shows an alternative routing of the fluid supply line 27 in a rotor blade 10 with a fluid jet module 21 being mounted at the same position as the fluid jet module 21 of FIG. 11. The fluid supply line 27 is routed in the chordwise direction from the fluid jet module 21 to the trailing edge 16 and therefrom along the trailing edge 16 in the direction of the root of the rotor blade 10 to a defined location on the trailing edge 16, where the fluid supply line 27 is again fed through a feed hole 32 and thereby through the outer surface of the rotor blade 10 to the inside 12 of the rotor blade 10.

(39) FIG. 13 shows yet another alternative routing of the fluid supply line 27 in a rotor blade 10 with a fluid jet module 21 being mounted at the same position as the fluid jet module 21 of FIG. 11. The fluid supply line 27 is again routed in chordwise direction from the fluid jet module 21 to the trailing edge 16. Thereafter, the fluid supply line 27 is routed along the trailing edge 16 and externally of the rotor blade 10 towards the root of the rotor blade 10.

(40) FIG. 14 also shows a rotor blade 10 in its full span. A fluid jet module 21 is mounted as an add-on onto the suction side 17 of the rotor blade 10 and is located outboard on the suction side 17 of the rotor blade 10. The fluid supply line 27 is routed in chordwise direction from the fluid jet module 21 to the trailing edge 16. Thereafter, the fluid supply line 27 is routed along the trailing edge 16 towards the root of the rotor blade 10 along the trailing edge 16. Alternatively, the fluid supply line 27 can be fed through a feed hole 32 in the shell 11 of the rotor blade 10 to the inside 12 of the rotor blade 10 as shown in FIGS. 11 and 12.

(41) In FIG. 15, a fluid jet module 21 is mounted as an add-on onto the pressure side 18 of a rotor blade 10. The fluid supply line 27 is not depicted in this figure but may be arranged as previously explained, in particular with reference to FIGS. 11 to 14.

(42) Although the present invention has been disclosed in the form of embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.

(43) For the sake of clarity, it is to be understood that the use of a or an throughout this application does not exclude a plurality, and comprising does not exclude other steps or elements.