ROTOR BLADE FOR A WIND POWER INSTALLATION, AND ASSOCIATED WIND POWER INSTALLATION

Abstract

Rotor blade for a wind power installation, rotor for a wind power installation, and wind power installation. The disclosure relates in particular to a rotor blade for a wind power installation, having a rotor blade length, having a profile depth established between a leading edge and a trailing edge, and having a profile thickness established between a suction side and a pressure side, wherein the rotor blade has a trailing edge region, which adjoins the trailing edge and extends with a region extent of less than 20%, in particular less than 10%, of the profile depth in the direction of the leading edge, wherein the trailing edge region has at least one acoustic opening.

Claims

1. A rotor blade for a wind power installation, comprising: a rotor blade body having: a rotor blade length, a profile depth between a leading edge and a trailing edge, a profile thickness between a suction side and a pressure side, and a trailing edge region that adjoins the trailing edge and extends with a region extent of less than 20% of the profile depth in a direction of the leading edge, wherein the trailing edge region has at least one acoustic opening.

2. The rotor blade according to claim 1, wherein the acoustic opening is closable.

3. The rotor blade according to claim 1, wherein: at least one section of the trailing edge region is formed by a suction-side trailing edge element and a pressure-side trailing edge element, which are arranged adjacent to one another in a direction of the profile thickness, and wherein at least one of the trailing edge elements and/or a screen between the trailing edge elements are/is arranged movably, wherein the at least one acoustic opening is open in an open position of the movably arranged trailing edge element and is substantially closed in a closed position of the movably arranged trailing edge element, and/or wherein the at least one acoustic opening is open in an open position of the screen and is substantially closed in a closed position of the screen.

4. The rotor blade according to claim 1, wherein the at least one acoustic opening is formed by a suction-side passage opening in the suction-side trailing edge element and by a pressure-side passage opening in the pressure-side trailing edge element

5. The rotor blade according to claim 3, wherein the movably arranged trailing edge element and/or the screen are configured to be arranged in such a way that the suction-side passage opening and the pressure-side passage opening are partially aligned.

6. The rotor blade according to claim 5, wherein the movably arranged trailing edge element and/or the screen are configured to be arranged between the open position and the closed position.

7. The rotor blade according to claim 3, wherein the movably arranged trailing edge element and/or the screen are mounted elastically in such a way that the movably arranged trailing edge element and/or the screen are moved from the closed position into the open position by a centrifugal force, wherein the centrifugal force is directed substantially in a direction of the rotor blade length and is induced during operation by a rotation of the rotor blade about a center of rotation.

8. The rotor blade according to claim 3, wherein the movably arranged trailing edge element and/or the screen are coupled to an actuator, wherein the actuator is configured to move the movably arranged trailing edge element and/or the screen between the closed position and the open position.

9. The rotor blade according to claim 8, wherein the actuator is a piezoceramic actuator.

10. The rotor blade according to claim 8, wherein the actuator is configured to move at a frequency of 200 Hz.

11. The rotor blade according to claim 1, wherein the at least one acoustic opening is arranged and formed in such a way that particles that enter the acoustic opening are removable by way of a centrifugal force.

12. The rotor blade according to claim 1, wherein the at least one acoustic opening is of conical form.

13. The rotor blade according to claim 1, wherein the at least one acoustic opening has a passage direction oriented in a direction of the profile thickness.

14. The rotor blade according to claim 13, wherein the at least one acoustic opening has a passage direction oriented in a direction of the rotor blade length and is V-shaped.

15. The rotor blade according to claim 1, wherein the at least one acoustic opening has a first entry and a second entry, wherein the acoustic opening extends with a passage direction between the first entry and the second entry, wherein the first entry is arranged on the pressure side and the second entry is arranged on the suction side, wherein the passage direction is substantially straight or substantially V-shaped with directional components in a direction of the profile thickness and/or a direction of the rotor blade length, and/or wherein the first entry and the second entry are arranged on the pressure side or on the suction side and the passage direction is curved in a semicircular or a semi-oval shape.

16. The rotor blade according to claim 1, wherein the trailing edge region, having the at least one acoustic opening, is produced by an additive method.

17. The rotor blade according to claim 1, wherein the region in which the trailing edge region extends is less than 10% of the profile depth in the direction of the leading edge.

18. A rotor for a wind power installation, comprising the rotor blade according to claim 1.

19. A wind power installation comprising the rotor according to claim 18.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0030] Preferred exemplary embodiments will be discussed by way of example on the basis of the appended figures. In the figures:

[0031] FIG. 1 shows a schematic three-dimensional view of a wind power installation;

[0032] FIG. 2 shows a schematic two-dimensional view of a profile section;

[0033] FIG. 3 shows a further schematic two-dimensional view of a profile section;

[0034] FIG. 4 shows a schematic two-dimensional view of the rotor blade shown in FIG. 1;

[0035] FIG. 5 shows a schematic three-dimensional view of a trailing edge region;

[0036] FIG. 6 shows a schematic two-dimensional detail view of acoustic openings in a trailing edge region in a closed position;

[0037] FIG. 7 shows a schematic two-dimensional view of acoustic openings in a trailing edge region in an open position;

[0038] FIG. 8 shows a schematic two-dimensional sectional view of a trailing edge region;

[0039] FIG. 9 shows a further schematic two-dimensional sectional view of a trailing edge region;

[0040] FIG. 10 shows a further schematic two-dimensional sectional view of a trailing edge region;

[0041] FIG. 11 shows a schematic three-dimensional view of a trailing edge region;

[0042] FIG. 12 shows a detail view of the profile elements shown in FIG. 11;

[0043] FIG. 13 shows a schematic two-dimensional view of the profile elements shown in FIG. 12; and

[0044] FIG. 14 shows schematic two-dimensional views of a further example of profile elements.

[0045] In the figures, identical or substantially functionally identical or similar elements are denoted by the same reference signs.

DETAILED DESCRIPTION

[0046] FIG. 1 shows a schematic three-dimensional view of a wind power installation 100. The wind power installation 100 has a tower 102 and a nacelle 104 on the tower 102. An aerodynamic rotor 106 having three rotor blades 108 and having a spinner 110 is provided on the nacelle 104. During the operation of the wind power installation 100, the aerodynamic rotor 106 is set in rotational motion by the wind and thereby also rotates an electrodynamic rotor or runner of a generator, which is coupled directly or indirectly to the aerodynamic rotor 106. The electric generator is arranged in the nacelle 104 and generates electrical energy.

[0047] At least one of the rotor blades 108 has a trailing edge region, which adjoins a trailing edge and extends with a region extent of less than 20%, in particular less than 10%, of the profile depth in the direction of the leading edge. The trailing edge region has at least one acoustic opening.

[0048] FIG. 2 shows a schematic two-dimensional view of a profile section. The rotor blade 108 extends with a profile depth between the leading edge 112 and the trailing edge 114. A profile thickness is established between the suction side 120 and the pressure side 122. The rotor blade has a trailing edge region 116 adjoining the trailing edge 114. The trailing edge region 116 has an acoustic opening 140. FIG. 3 shows a further profile section of the rotor blade 108. The trailing edge region 116 has in particular a plurality of acoustic openings 140. The acoustic openings extend from the suction side 120 as passage openings to the pressure side 122. The orientation of the acoustic openings 140, in particular the passage axis thereof, is oriented substantially parallel to the profile thickness. Exemplary sections along an axis A are shown in FIGS. 8 to 10.

[0049] FIG. 4 shows a schematic two-dimensional view of the rotor blade 108 shown in FIG. 1. The rotor blade 108 extends with a rotor blade length from a blade root 124 to a blade tip 126. Orthogonally thereto, the rotor blade 108 extends with the profile depth from the leading edge 112 to the trailing edge 114. Proceeding from the trailing edge 114, the trailing edge region 116 extends in the direction of the leading edge 112. This extent in the direction of the leading edge 112 occurs with a region extent which amounts to less than 20% of the profile depth. In the direction of the rotor blade length, the trailing edge region extends with a trailing edge region longitudinal extent which is smaller than the rotor blade length. The axis A is also shown here, along which axis exemplary sections in FIGS. 8 to 10 extend.

[0050] FIG. 5 shows a schematic three-dimensional view of a trailing edge region 116. The trailing edge region 116 is formed by a suction-side trailing edge element 130 and a pressure-side trailing edge element 132. The suction-side trailing edge element 130 and the pressure-side trailing edge element 132 are arranged adjacent to one another in the direction of the profile thickness. The acoustic opening 140 passes through the trailing edge elements 130, 132. For this purpose, the suction-side trailing edge element 130 has a suction-side passage opening and the pressure-side trailing edge element 132 has a pressure-side passage opening.

[0051] If said passage openings are aligned with one another, the acoustic opening 140 is open. If the passage openings are not aligned with one another, the acoustic opening 140 is closed. In order to make possible closing and opening of the acoustic opening 140, the suction-side trailing edge element 130 is arranged movably. Furthermore, the suction-side trailing edge element 130 is coupled to an actuator 134 via a coupling element 136. By means of the actuator 134, the suction-side trailing edge element 130 can be moved back and forth in the direction of the rotor blade length. The back-and-forth movement of the suction-side trailing edge element 130 results in the suction-side passage opening likewise being moved. Consequently, by means of the actuator 134, it is possible to set whether the suction-side passage opening is aligned with the pressure-side passage opening and the acoustic opening 140 is thus open, or whether the passage openings are not aligned with one another and the acoustic opening 140 is thus closed. By way of the movement of the suction-side trailing edge element 130, this is moved back and forth between an open position and a closed position.

[0052] FIGS. 6 and 7 illustrate the function of the open position and of the closed position. The acoustic opening 140 is formed by the suction-side passage opening 142 and the pressure-side passage opening 144. In the closed position, which is illustrated in FIG. 6, the suction-side passage opening 142 does not share a common passage axis with the pressure-side passage opening 144. The acoustic opening 140 is therefore closed.

[0053] In FIG. 7, the suction-side trailing edge element 130 has been displaced in such a way that the suction-side passage opening 142 is aligned with the pressure-side passage opening 144 and shares a common passage axis therewith. Consequently, the acoustic opening 140 is open and is thus in an open position.

[0054] FIGS. 8 to 10 illustrate different forms of the acoustic openings 140 in a cross section along the axes A in FIGS. 3 and 4. FIG. 8 shows a passage opening with a straight passage axis which has directional components in the direction of the rotor blade length and the direction of the profile thickness. In FIG. 9, the acoustic opening 140 is V-shaped, in each case also with directional components in the direction of the rotor blade length and the direction of the rotor blade thickness. Due to the form of these acoustic openings 140, a particle 148 can be thrown out of the acoustic opening 140 by a centrifugal force in a centrifugal force direction 146, 147. The acoustic openings 140 shown in FIG. 10 each have entries and exits which are arranged on one side, for example the pressure side.

[0055] FIG. 11 shows a schematic three-dimensional view of a trailing edge region. The trailing edge segment 200 has a first profile element 202, a second profile element 204 and a third profile element 206. In FIG. 12, it is shown that the first profile element 202 has a first movable segment 208. The first movable segment 208 is arranged so as to be movable at the first center of rotation 210. The second profile element 204 has, analogously to the first profile element 202, a second movable segment 212 with a second center of rotation 214. Due to the centers of rotation, the movable segments 208, 212 can be moved in the direction of movement 216. This arrangement allows the width of the profile elements 202, 204, 206 to be enlarged. This is advantageously also achieved in that the first profile element 202 is arranged on a fixed bearing 218 and the further bearing points 220, 222 are arranged displaceably, as is shown in particular in FIG. 13. The system is furthermore realized in that the profile elements 202, 204, 206 are coupled to a spring element 224.

[0056] At low wind speeds or rotational speeds, it is still the case that no large centrifugal force acts, and the spring force of the spring element 224 can compensate the centrifugal force and holds the profile elements so firmly that a large region of overlap exists at the teeth and the ratio width to length of the segments is still relatively small. If the wind speed increases, the rotational speed increases and, as a consequence, the centrifugal force increases. Since the profile elements are fixed on one side, a force acts on the segments and the teeth are drawn widthwise.

[0057] The noise-reduction capability of the profile elements 202, 204, 206 can thus be adapted during operation, with the result that the efficiency range is increased or, in certain speed ranges, the noise emission of the installation is influenced. In particular, in a lower speed range, it is possible to work with a different geometry than at the rated power. Here, it is particularly preferably the case that the spring force of the exemplary spring element 224 is matched to the operating characteristic curve such that, according to requirement, the serration width can be adapted according to the acoustically optimum width via the wind speed. In this region, the acoustic opening is the region remaining free between the profile elements 202, 204, 206, which varies as the geometry of the profile elements 202, 204, 206 varies.

[0058] FIG. 14 shows two schematic two-dimensional views of profile elements which can interact with all of the trailing edge segments described and form a further example of acoustic openings.

[0059] The profile elements 302, 304 are designed as a multi-layer construction, wherein the layers of the profile elements 302, 304 are displaceable relative to one another along a direction 308, whereby different geometries are obtained. In this example, each of the profile elements 302, 304 has a plurality of serrations. In other embodiments, the individual serrations may also be formed as individual profile elements. The displacement of the profile elements 302, 304 may be controlled passively, but also actively. In the passive case, just as in FIGS. 12 and 13, at the spanwise end of at least one of the profile elements 302, 304, there are situated elastic elements, a spring element 324 on the profile element 302 in this example. The force on the spring element 324 varies according to rotational speed, and the profile elements 302, 304, driven by the centrifugal force, can move outwards and work against a spring force. In this case, the geometry of the profile elements 302, 304 and the elastic stiffness of the spring element 324 are preferably matched to one another.

[0060] In the active case, instead of the elastic elements, actuators, such as for example piezo actuators, which actively control the movement of the profile elements, are installed. In this way, it is possible to actively influence the noise emission, and thus achieve a desired noise profile, in the operating range of the wind power installation.

[0061] A preferred configuration of the profile elements 302, 304 is, as shown in FIG. 14, a construction from segments of, by way of example, three serrations, which are connected to one another at the serration base and are mounted displaceably on a rail 306. FIG. 14 shows a state 320 when the wind power installation is starting up, or at low rotational speeds, in which the profile elements 302 and 304 are displaced in relation to one another. The layer of the profile element 302 is displaced when the rotational speed is increased, such that a state 310 in which the layer of the profile element 302 is situated so as to be congruent with the layer of the profile element 304—in particular at the rated power—is established.

REFERENCE SIGNS

[0062] 100 Wind power installation

[0063] 102 Tower

[0064] 104 Nacelle

[0065] 106 Rotor

[0066] 108 Rotor blades

[0067] 110 Spinner

[0068] 112 Leading edge

[0069] 114 Trailing edge

[0070] 116 Trailing edge region

[0071] 140 Acoustic opening

[0072] 120 Suction side

[0073] 122 Pressure side

[0074] 124 Blade root

[0075] 126 Blade tip

[0076] 130 Suction-side trailing edge element

[0077] 132 Pressure-side trailing edge element

[0078] 134 Actuator

[0079] 136 Coupling element

[0080] 142 Suction-side passage opening

[0081] 144 Pressure-side passage opening

[0082] 147 Centrifugal force direction

[0083] 146 Centrifugal force direction

[0084] 148 Particle

[0085] 200 Trailing edge segment

[0086] 202 First profile element

[0087] 204 Second profile element

[0088] 206 Third profile element

[0089] 208 First movable segment

[0090] 210 First center of rotation

[0091] 212 Second movable segment

[0092] 214 Second center of rotation

[0093] 216 Direction of movement

[0094] 218 Fixed bearing

[0095] 220, 222 Displaceable bearing points

[0096] 224 Spring element

[0097] 302, 304 Profile element

[0098] 306 Rail

[0099] 308 Direction

[0100] 310 State

[0101] 320 State

[0102] 324 Spring element

[0103] The various embodiments described above can be combined to provide further embodiments. These and other changes can be made to the embodiments in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure.