WO2014048581A1 - A wind turbine blade with a noise reducing device - Google Patents

A wind turbine blade with a noise reducing device Download PDF

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Publication number
WO2014048581A1
WO2014048581A1 PCT/EP2013/052728 EP2013052728W WO2014048581A1 WO 2014048581 A1 WO2014048581 A1 WO 2014048581A1 EP 2013052728 W EP2013052728 W EP 2013052728W WO 2014048581 A1 WO2014048581 A1 WO 2014048581A1
Authority
WO
WIPO (PCT)
Prior art keywords
wind turbine
trailing edge
turbine blade
spines
blade according
Prior art date
Application number
PCT/EP2013/052728
Other languages
French (fr)
Inventor
Peder Bay Enevoldsen
Original Assignee
Siemens Aktiengesellschaft
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Siemens Aktiengesellschaft filed Critical Siemens Aktiengesellschaft
Publication of WO2014048581A1 publication Critical patent/WO2014048581A1/en

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
    • F03D—WIND MOTORS
    • F03D1/00—Wind motors with rotation axis substantially parallel to the air flow entering the rotor 
    • F03D1/06—Rotors
    • F03D1/0608—Rotors characterised by their aerodynamic shape
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
    • F03D—WIND MOTORS
    • F03D1/00—Wind motors with rotation axis substantially parallel to the air flow entering the rotor 
    • F03D1/06—Rotors
    • F03D1/065—Rotors characterised by their construction elements
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
    • F05B2260/00—Function
    • F05B2260/96—Preventing, counteracting or reducing vibration or noise
    • F05B2260/962—Preventing, counteracting or reducing vibration or noise by means creating "anti-noise"
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/70—Wind energy
    • Y02E10/72—Wind turbines with rotation axis in wind direction

Definitions

  • a WIND TURBINE BLADE WITH A NOISE REDUCING DEVICE The present invention relates to a wind turbine blade having a noise reducing device attached at its trailing edge.
  • Wind turbine blades generate aerodynamic noise when the wind turbine operates and the rotor is in rotational movement.
  • aerodynamic noise source mechanism for lifting air ⁇ foils can be classified as follows: a) turbulent boundary- layer flow shed off of the trailing edge, b) separated boundary-layer and stalled airfoil flow, c) vortex shedding due to laminar boundary-layer instabilities, and d) vortex shedding from blunt trailing edges.
  • Noise sets a limitation on how close a wind turbine can be built to residential areas and at what rotational frequency a rotor of a wind turbine can rotate.
  • EP 0652367 Al proposes a wind turbine having a trailing edge with a saw-tooth form.
  • a saw- tooth-shaped strip can be used which is fixed to the trailing edge of the rotor blade.
  • US 2008/0166241 Al discloses a wind turbine blade brush with bristles or a brush disposed on an outer surface of the wind turbine blade.
  • the function of the bristles is to achieve a noise reduction effect.
  • the bristles can be arranged in at least one row along a longitudinal direction of the blade or in the vicinity of a trailing edge.
  • DE 10340978 Bl similarly discloses a wind turbine blade with a brush attached to the trailing edge wherein single fibers of the brush branch out. The branches of the brush imitate feathers of an owl. It is an object of the present invention to provide a wind turbine blade with an efficient noise reducing device.
  • the noise reducing device comprises a trailing edge comb with multiple aligned spines.
  • the present invention is based on the idea that aerodynamic noise can be reduced significantly by using a trailing edge comb comprising several spines which are positioned in a certain distance from each other. Each spine has a
  • the diameter of a spine decreases towards the trailing edge. This means that the smaller diameter of a spine is at the outer side of the trailing edge.
  • said multiple aligned spines are arranged in parallel at the trailing edge.
  • the trailing edge comb comprises aligned spines which differ in diameter and/or stiffness and/or length.
  • the trailing edge comb comprises aligned spines with a different distance between adjacent spines.
  • Each trailing edge comb has to be specifically adapted to the airfoil of the wind turbine blade and its dimensions. Another factor which influences the effect of the trailing edge comb is the projected rotational speed of the wind turbine blade. In every case the properties and dimensions of the spines have to be adapted to the wind turbine blade.
  • trailing edge comb for the inventive wind turbine blade comprising two or more layers of combs stacked one above another, whereby spines of one layer preferably cover a space between adjacent spines of another layer.
  • spines of different layers have different properties and dimensions.
  • the trailing edge comb can be arranged in a section ranging approximately from 75 % to 95 % of the span. It was found out that this section is particularly relevant in order to reduce aerodynamic noise by using a trailing edge comb.
  • the trailing edge comb is printed by a 3D printer.
  • This production technology allows to give the trailing edge comb and its spines varying stiffness within the structure.
  • the trailing edge comb can be made of casted plastic or cut out and machined from a plate.
  • the invention further relates to a wind turbine, comprising a tower, an electrical generator with a rotor shaft and a hub to which wind turbine blades are connected.
  • the inventive wind turbine comprises said inventive wind turbine blades.
  • fig. 1 is a top view of an inventive wind turbine blade
  • fig. 2 is a perspective view of a trailing edge comb
  • fig. 3 is a sectional view of an inventive wind turbine blade with several trailing edge combs.
  • Fig. 1 is a top view of a wind turbine blade 1 with a blade root 2 by which it is connected to a hub of a rotor, which is part of an electrical generator. Further the wind turbine blade 1 comprises a trailing edge 3, a leading edge 4 and a blade tip 5. At the trailing edge 3 a noise reducing device is attached which is formed as a trailing edge comb 6. Said trailing edge comb 6 is attached in a section ranging from about 75 % to 95 % of the span of the wind turbine blade 1.
  • Fig. 2 is a perspective view of the trailing edge comb 6.
  • the trailing edge comb 6 comprises of aligned spines 7, whereby each spine has a decreasing
  • All spines 7 are arranged in parallel and the size and diameter of the spines 7 can be modified in order to influence and adjust the noise reducing effect. Another factor is the distance between adjacent spines, which is chosen with regard to the aerodynamic and noise reducing effect.
  • the outer ends of spines 7 are attached on or close to the trailing edge 3.
  • outer ends of spines extend from the trailing edge to the outside so that the spines are only partially disposed on the trailing edge.
  • the inner end of spines 7 of trailing edge comb 6 is attached to the trailing edge 3, the opposite outer end of spines 7 extends from the trailing edge 3.
  • Fig. 3 is a cross-sectional view and shows a trailing edge comb 8 arranged on the trailing edge 3.
  • Trailing edge comb 8 comprises two layers of spines 9, 10 which are stacked above one another.
  • the lower layer consisting of spines 9 has larger cross- sections compared to the upper layer of spines 10.
  • spines 10 of the upper layer partially cover a space between adjacent spines 9 of the lower layer.
  • spines 9, 10 are printed with a 3D printer. Using this production technology several spines with slightly different dimensions and varying stiffness within the
  • Spines 9, 10 are made from a plastic material. Other materials are possible, too, for example casted plastic or metal, in particular aluminium or steel .
  • the use of the trailing edge comb as noise reducing device significantly improves the emission of noise during rotation of the wind turbine blade. Consequently such wind turbines can be built closer to residential areas.

Abstract

A wind turbine blade (1) having a noise reducing device attached at its trailing edge (3), whereby the noise reducing device comprises a trailing edge comb (6, 8) with multiple aligned spines (7, 9, 10).

Description

Description
A WIND TURBINE BLADE WITH A NOISE REDUCING DEVICE The present invention relates to a wind turbine blade having a noise reducing device attached at its trailing edge.
Wind turbine blades generate aerodynamic noise when the wind turbine operates and the rotor is in rotational movement. In general aerodynamic noise source mechanism for lifting air¬ foils can be classified as follows: a) turbulent boundary- layer flow shed off of the trailing edge, b) separated boundary-layer and stalled airfoil flow, c) vortex shedding due to laminar boundary-layer instabilities, and d) vortex shedding from blunt trailing edges.
It was found out that the main force of aerodynamic noise originates at the trailing edge of the outer span of wind turbine blades. A surprising finding was that noise from the blade tip is of minor importance. It was also found that noise produced by the blades is proportional to the wind speed (i.e. rotational speed) at the blades.
Noise sets a limitation on how close a wind turbine can be built to residential areas and at what rotational frequency a rotor of a wind turbine can rotate.
It is well known to optimise wind turbine blades in the design phase to reduce aerodynamic noise. The attachment of noise reducing devices to the trailing edge of wind turbine blades as a retrofit or after production is well known in the wind turbine industry. One example for a noise reducing device is a serrated plastic plate as a part of a retrofit package attached to the trailing edge of wind turbine blades. The attachment or production of wind turbine blades with winglets is another means to reduce noise from the wind turbine blade. EP 1314885 Al discloses a flexible serrated trailing edge for wind turbine rotor blades. In order to improve the efficiency of an existing wind turbine rotor it is proposed to attach a serrated panel to at least a part of the trailing edge of the wind turbine blades. By using serrated trailing edges the lift and drag characteristics of a lifting surface can be improved .
EP 0652367 Al proposes a wind turbine having a trailing edge with a saw-tooth form. In order to obtain this form a saw- tooth-shaped strip can be used which is fixed to the trailing edge of the rotor blade.
US 2008/0166241 Al discloses a wind turbine blade brush with bristles or a brush disposed on an outer surface of the wind turbine blade. The function of the bristles is to achieve a noise reduction effect. The bristles can be arranged in at least one row along a longitudinal direction of the blade or in the vicinity of a trailing edge. DE 10340978 Bl similarly discloses a wind turbine blade with a brush attached to the trailing edge wherein single fibers of the brush branch out. The branches of the brush imitate feathers of an owl. It is an object of the present invention to provide a wind turbine blade with an efficient noise reducing device.
According to the present invention this object is achieved in the above defined wind turbine blade in that the noise reducing device comprises a trailing edge comb with multiple aligned spines. The present invention is based on the idea that aerodynamic noise can be reduced significantly by using a trailing edge comb comprising several spines which are positioned in a certain distance from each other. Each spine has a
longitudinal shape and is formed on the surface of the trailing edge.
According to a further development of the invention the diameter of a spine decreases towards the trailing edge. This means that the smaller diameter of a spine is at the outer side of the trailing edge.
Preferably said multiple aligned spines are arranged in parallel at the trailing edge.
In an embodiment of the invention the trailing edge comb comprises aligned spines which differ in diameter and/or stiffness and/or length. As an alternative the trailing edge comb comprises aligned spines with a different distance between adjacent spines. Each trailing edge comb has to be specifically adapted to the airfoil of the wind turbine blade and its dimensions. Another factor which influences the effect of the trailing edge comb is the projected rotational speed of the wind turbine blade. In every case the properties and dimensions of the spines have to be adapted to the wind turbine blade.
It is possible to use a trailing edge comb for the inventive wind turbine blade comprising two or more layers of combs stacked one above another, whereby spines of one layer preferably cover a space between adjacent spines of another layer. In this regard it can be envisaged that spines of different layers have different properties and dimensions. According to the invention the trailing edge comb can be arranged in a section ranging approximately from 75 % to 95 % of the span. It was found out that this section is particularly relevant in order to reduce aerodynamic noise by using a trailing edge comb.
In order to simplify the production of the trailing edge comb it can be envisaged that the trailing edge comb is printed by a 3D printer. This production technology allows to give the trailing edge comb and its spines varying stiffness within the structure. However, as an alternative the trailing edge comb can be made of casted plastic or cut out and machined from a plate.
The invention further relates to a wind turbine, comprising a tower, an electrical generator with a rotor shaft and a hub to which wind turbine blades are connected.
The inventive wind turbine comprises said inventive wind turbine blades.
The invention and its underlying principle will be better understood when consideration is given to the following detailed description of preferred embodiments.
In the accompanying drawings : fig. 1 is a top view of an inventive wind turbine blade; fig. 2 is a perspective view of a trailing edge comb; fig. 3 is a sectional view of an inventive wind turbine blade with several trailing edge combs.
Fig. 1 is a top view of a wind turbine blade 1 with a blade root 2 by which it is connected to a hub of a rotor, which is part of an electrical generator. Further the wind turbine blade 1 comprises a trailing edge 3, a leading edge 4 and a blade tip 5. At the trailing edge 3 a noise reducing device is attached which is formed as a trailing edge comb 6. Said trailing edge comb 6 is attached in a section ranging from about 75 % to 95 % of the span of the wind turbine blade 1.
Fig. 2 is a perspective view of the trailing edge comb 6. As can be seen in fig. 2 the trailing edge comb 6 comprises of aligned spines 7, whereby each spine has a decreasing
diameter towards its outer end. All spines 7 are arranged in parallel and the size and diameter of the spines 7 can be modified in order to influence and adjust the noise reducing effect. Another factor is the distance between adjacent spines, which is chosen with regard to the aerodynamic and noise reducing effect. According to one embodiment the outer ends of spines 7 are attached on or close to the trailing edge 3. However, other embodiments are possible, whereby outer ends of spines extend from the trailing edge to the outside so that the spines are only partially disposed on the trailing edge. In this embodiment the inner end of spines 7 of trailing edge comb 6 is attached to the trailing edge 3, the opposite outer end of spines 7 extends from the trailing edge 3.
Fig. 3 is a cross-sectional view and shows a trailing edge comb 8 arranged on the trailing edge 3.
Trailing edge comb 8 comprises two layers of spines 9, 10 which are stacked above one another. The lower layer consisting of spines 9 has larger cross- sections compared to the upper layer of spines 10.
Accordingly spines 10 of the upper layer partially cover a space between adjacent spines 9 of the lower layer. In this embodiment spines 9, 10 are printed with a 3D printer. Using this production technology several spines with slightly different dimensions and varying stiffness within the
structure can be produced. Spines 9, 10 are made from a plastic material. Other materials are possible, too, for example casted plastic or metal, in particular aluminium or steel . The use of the trailing edge comb as noise reducing device significantly improves the emission of noise during rotation of the wind turbine blade. Consequently such wind turbines can be built closer to residential areas. Although the present invention has been described in detail with reference to the preferred embodiment, the present invention is not limited by the disclosed examples from which the skilled person is able to derive other variations without departing from the scope of the invention.

Claims

A wind turbine blade (1) having a noise reducing device attached at its trailing edge (3) , characterized in that the noise reducing device comprises a trailing edge comb (6, 8) with multiple aligned spines (7, 9, 10) .
A wind turbine blade according to claim 1, characterized in that the diameter of a spine (7, 9, 10) decreases towards the outer side of the trailing edge (3) .
A wind turbine blade according to claim 1 or 2,
characterized in that multiple aligned spines (7, 9, 10) are arranged in parallel.
A wind turbine blade according to any of the preceding claims, characterized in that the trailing edge comb (6, 8) comprises aligned spines (7, 9, 10) which differ in diameter and/or stiffness and/or length or aligned spines with a different distance between adjacent spines (7, 9, 10) .
A wind turbine blade according to any of the preceding claims, characterized in that the trailing edge comb (8) comprises two or more layers of combs stacked above one another, whereby spines (10) of one layer preferably cover a space between adjacent spines (9) of another layer .
A wind turbine blade according to claim 5, characterized in that spines (9, 10) of different layers have
different properties and dimensions.
A wind turbine blade according to any of the preceding claim, characterized in that the trailing edge comb (6, 8) is arranged in a section ranging approximately from 75 % to 95 % of the span.
8. A wind turbine blade according to any of the preceding claims, characterized in that the trailing edge comb (6, 8) is printed by a 3D printer.
9. A wind turbine blade according to any of claims 1 to 7, characterized in that the trailing edge comb (6, 8) is made of casted plastic or cut out and machined from a plate .
10. A wind turbine, comprising a tower, an electrical
generator with a rotor shaft and a hub to which wind turbine blades are connected, characterized in that the wind turbine comprises wind turbine blades according to any of claims 1 to 9.
PCT/EP2013/052728 2012-09-25 2013-02-12 A wind turbine blade with a noise reducing device WO2014048581A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
EP12185966.4 2012-09-25
EP12185966 2012-09-25

Publications (1)

Publication Number Publication Date
WO2014048581A1 true WO2014048581A1 (en) 2014-04-03

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Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104976075A (en) * 2014-04-14 2015-10-14 西门子公司 Vortex generators aligned with trailing edge features on wind turbine blade
WO2015192915A1 (en) * 2014-06-18 2015-12-23 Siemens Aktiengesellschaft Rotor blade with noise reduction means
WO2015193654A1 (en) * 2014-06-16 2015-12-23 Brunel University Noise reduction to the trailing edge of fluid dynamic bodies
US10400744B2 (en) 2016-04-28 2019-09-03 General Electric Company Wind turbine blade with noise reducing micro boundary layer energizers
EP3587799A1 (en) * 2018-06-27 2020-01-01 Siemens Gamesa Renewable Energy A/S Aerodynamic structure
US10746157B2 (en) 2018-08-31 2020-08-18 General Electric Company Noise reducer for a wind turbine rotor blade having a cambered serration
US11359600B2 (en) 2018-06-27 2022-06-14 Siemens Gamesa Renewable Energy A/S Aerodynamic structure
EP3696402B1 (en) 2019-02-18 2022-07-20 LM Wind Power A/S Noise reducer for a wind turbine rotor blade
WO2023205270A1 (en) * 2022-04-20 2023-10-26 National Technology & Engineering Solutions Of Sandia, Llc Wind turbine blades having system integrated tips and methods of making using additive manufacturing

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0652367A1 (en) 1993-11-04 1995-05-10 Stork Product Engineering B.V. Noise reduction for wind turbine
EP1314885A1 (en) 2001-11-26 2003-05-28 Bonus Energy A/S Flexible serrated trailing edge for wind turbine rotor blade
WO2008035149A2 (en) * 2006-02-23 2008-03-27 Stichting Nationaal Lucht- En Ruimtevaart Laboratorium Rotor blade for a wind turbine
US20080166241A1 (en) 2007-01-04 2008-07-10 Stefan Herr Wind turbine blade brush
DE10340978B4 (en) 2003-09-05 2008-09-18 Moosdorf, Reinhard W. Synthetic fiber element for rotor blades
US20120134837A1 (en) * 2011-12-19 2012-05-31 General Electric Company Noise reducer for rotor blade in wind turbine
EP2570656A1 (en) * 2011-09-19 2013-03-20 Nordex Energy GmbH Wind energy assembly rotor blade with a thick profile trailing edge

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0652367A1 (en) 1993-11-04 1995-05-10 Stork Product Engineering B.V. Noise reduction for wind turbine
EP1314885A1 (en) 2001-11-26 2003-05-28 Bonus Energy A/S Flexible serrated trailing edge for wind turbine rotor blade
DE10340978B4 (en) 2003-09-05 2008-09-18 Moosdorf, Reinhard W. Synthetic fiber element for rotor blades
WO2008035149A2 (en) * 2006-02-23 2008-03-27 Stichting Nationaal Lucht- En Ruimtevaart Laboratorium Rotor blade for a wind turbine
US20080166241A1 (en) 2007-01-04 2008-07-10 Stefan Herr Wind turbine blade brush
EP2570656A1 (en) * 2011-09-19 2013-03-20 Nordex Energy GmbH Wind energy assembly rotor blade with a thick profile trailing edge
US20120134837A1 (en) * 2011-12-19 2012-05-31 General Electric Company Noise reducer for rotor blade in wind turbine

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104976075B (en) * 2014-04-14 2020-04-10 西门子歌美飒可再生能源公司 Vortex generators aligned with trailing edge features on wind turbine blades
CN104976075A (en) * 2014-04-14 2015-10-14 西门子公司 Vortex generators aligned with trailing edge features on wind turbine blade
EP2933475A1 (en) * 2014-04-14 2015-10-21 Siemens Aktiengesellschaft Vortex generators aligned with trailing edge features on wind turbine blade
US9476406B2 (en) 2014-04-14 2016-10-25 Siemens Aktiengesellschaft Vortex generators aligned with trailing edge features on wind turbine blade
WO2015193654A1 (en) * 2014-06-16 2015-12-23 Brunel University Noise reduction to the trailing edge of fluid dynamic bodies
US10900465B2 (en) 2014-06-16 2021-01-26 Brunel University London Noise reduction to the trailing edge of fluid dynamic bodies
WO2015192915A1 (en) * 2014-06-18 2015-12-23 Siemens Aktiengesellschaft Rotor blade with noise reduction means
US11181093B2 (en) 2014-06-18 2021-11-23 Siemens Gamesa Renewable Energy A/S Rotor blade with noise reduction means
US10400744B2 (en) 2016-04-28 2019-09-03 General Electric Company Wind turbine blade with noise reducing micro boundary layer energizers
EP3587799A1 (en) * 2018-06-27 2020-01-01 Siemens Gamesa Renewable Energy A/S Aerodynamic structure
CN110645140A (en) * 2018-06-27 2020-01-03 西门子歌美飒可再生能源公司 Aerodynamic structure
US11236722B2 (en) 2018-06-27 2022-02-01 Siemens Gamesa Renewable Energy A/S Aerodynamic structure
US11359600B2 (en) 2018-06-27 2022-06-14 Siemens Gamesa Renewable Energy A/S Aerodynamic structure
CN110645140B (en) * 2018-06-27 2022-10-21 西门子歌美飒可再生能源公司 Aerodynamic structure
US10746157B2 (en) 2018-08-31 2020-08-18 General Electric Company Noise reducer for a wind turbine rotor blade having a cambered serration
EP3696402B1 (en) 2019-02-18 2022-07-20 LM Wind Power A/S Noise reducer for a wind turbine rotor blade
WO2023205270A1 (en) * 2022-04-20 2023-10-26 National Technology & Engineering Solutions Of Sandia, Llc Wind turbine blades having system integrated tips and methods of making using additive manufacturing

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