ADAPTABLE SPOILER FOR A WIND TURBINE BLADE

Abstract

Provided is an adaptable spoiler for a wind turbine blade, including: a flexible body including: an outer surface to be exposed to air flow; an internal surface limiting a cavity to be inflated with fluid to different level, wherein a shape and/or position and/or orientation of the surface to be exposed to air flow changes upon inflating the cavity to different level.

Claims

1. An adaptable spoiler for a wind turbine blade, comprising: a flexible body including: an outer surface to be exposed to air flow; an internal surface limiting a cavity to be inflated with fluid to different level, wherein a shape and/or position and/or orientation of the surface to be exposed to air flow changes upon inflating the cavity to different level.

2. The adaptable spoiler according to claim 1, wherein the outer surface to be exposed to air flow is at least in part airfoil shaped.

3. The adaptable spoiler according to claim 1, further comprising: at least one stiff element, distinct from the body and having a surface to be air flow exposed, wherein the stiff element is attached to the body such that a protrusion height (ha, hb) and/or tilt angle (α) of the surface of the stiff element changes upon inflating the cavity to different level.

4. The adaptable spoiler according to claim 3, wherein the stiff element has an airfoil shape or plane shape.

5. The adaptable spoiler according to claim 1, the spoiler comprising: a stiff connection structure adapted to be connected at a rotor blade surface, wherein the body is coupled to the connection structure.

6. The adaptable spoiler according to claim 5, the connection structure comprising an upper engagement portion and a lower engagement portion, in particular forming a slit between, the body comprising an engageable portion configured to be engaged by the upper and lower engagement portions of the connection structure, in particular by inserting into the slit and latching within the slit by at least one notch mating with at least one protruding element.

7. The adaptable spoiler according to claim 6, wherein the outer surface and the internal surface of the body is arranged in an air flow direction downstream the engageable portion.

8. The adaptable spoiler according to claim 1, the body further comprising: a further internal surface limiting a further cavity to be inflated with fluid to different level for further adapting the spoiler to different aerodynamic properties.

9. The adaptable spoiler according to claim 8, wherein the further internal surface is arranged within the body in a flow direction downstream the internal surface.

10. The adaptable spoiler according to claim 9, further comprising: a vortex generator formed at the body to be exposed to air flow, wherein upon inflating the cavity and/or the further cavity to different level, the aerodynamic influence of the vortex generator changes.

11. The adaptable spoiler according to claim 1, wherein the more air is deflected away from the vortex generator the more the cavity is inflated and the less the further cavity is inflated.

12. The adaptable spoiler according to claim 1, wherein the body extends along a longitudinal direction of the rotor blade over an entire longitudinal extent of the spoiler, is continuous and integrally formed.

13. The adaptable spoiler according to claim 1, further comprising: a hydraulic and/or pneumatic apparatus arranged and configured to inflate or deflate the cavity and/or the further cavity to different level.

14. A rotor blade for a wind turbine, comprising: a blade airfoil surface; and an adaptable spoiler according to claim 1 installed at the blade airfoil surface.

15. The rotor blade according to claim 14, further comprising: a flow regulating device, in particular comprising at least one vortex generator, installed at the blade airfoil surface downstream the spoiler, wherein depending on a state of the adaptable spoiler, the effect of the flow regulating device on the air flow is changed.

16. The adaptable spoiler according to claim 3, further comprising: at least one stiff element, segmented along longitudinal surfaces.

17. The adaptable spoiler according to claim 12, wherein the body extends along a longitudinal direction of the rotor blade over the entire longitudinal extent of the spoiler, is continuous and integrally formed, and comprising at least one of but not limited to: natural rubber, thermoplastic elastomers as TPV or TPU, silicone, or a combination thereof.

18. A rotor blade for a wind turbine, of claim 14, further comprising the adaptable spoiler installed at the blade airfoil surface, in a front portion of a suction surface.

Description

BRIEF DESCRIPTION

[0043] Some of the embodiments will be described in detail, with reference to the following figures, wherein like designations denote like members, wherein:

[0044] FIG. 1 schematically illustrates a rotor blade for a wind turbine according to an embodiment of the present invention comprising an adaptable spoiler according to an embodiment of the present invention;

[0045] FIG. 2 schematically illustrates rotor blades for a wind turbine according to different embodiments of the present invention comprising an adaptable spoiler in an extended state according to different embodiments of the present invention;

[0046] FIG. 3 schematically illustrates rotor blades for a wind turbine according to different embodiments of the present invention comprising an adaptable spoiler in a retracted state according to different embodiments of the present invention;

[0047] FIG. 4 schematically illustrates rotor blades for a wind turbine according to another embodiment of the present invention comprising an adaptable spoiler fully extended according to another embodiment of the present invention;

[0048] FIG. 5 schematically illustrates rotor blades for a wind turbine according to another embodiment of the present invention comprising an adaptable spoiler fully retracted according to another embodiment of the present invention;

[0049] FIG. 6 represents a disassembled spoiler;

[0050] FIG. 7 illustrates a situation in which the cavity as well as the further cavity are fully deflated such that the vortex generator is entirely exposed to the air flow;

[0051] FIG. 8 illustrates the situation in which the cavity is fully inflated, while the further cavity is fully deflated; and

[0052] FIG. 9 illustrates the situation in which both, the cavity as well as the further cavity are fully inflated.

DETAILED DESCRIPTION

[0053] Elements depicted in FIGS. 1 to 9, similar in structure and/or function are labeled in the different figures with reference signs only different in the first digit. A description of one element not described with reference to a particular embodiment may be taken from the description of this element as provided in the description of another embodiment.

[0054] The suction side portion of the rotor blade 100 schematically illustrated in FIG. 1 in a sectional view viewing along the longitudinal direction 101 of the rotor blade 100 comprises a rotor blade body 103 having a blade airfoil surface 105 at a suction side. The rotor blade 100 has a leading edge 109 and a trailing edge 111. The rotor blade 100 further comprises an adaptable spoiler 150 according to an embodiment of the present invention which is installed at the suction side blade airfoil surface 105 of the rotor blade 100.

[0055] The adaptable spoiler 150 comprises a flexible body 113 made from a flexible, deformable and elastic material, in particular being continuous forming a single component. The flexible body 113 comprises an outer surface 115 which is to be exposed to air flow. The adaptable spoiler 150 further comprises an internal surface 117 limiting a cavity 119 to be inflated with fluid (such as air, but for example also other fluids such as inert gases) to a different degree (for example to a different pressure). The shape of the surface 115 to be exposed to air flow changes upon inflating the cavity 119 to different degree. Since the flexible body 113 is made of a flexible deformable material, the shape of the internal surface 117 of the cavity 119 will change, in particular expand when the cavity 119 is inflated. Due to the extension of the cavity 119 also the outer surface 115 will expand or in general change shape, for example regarding protrusion height and/or in general an active flow-influencing profile. In particular, the upper surface of the body 113 comprises a bellow region 121 comprising a zigzag-shaped surface portion, facilitating increasing or decreasing the area of the internal surface 117 upon changing the volume of the cavity 119 while reducing also the internal strains in the materials. At least in a region 123 of the outer surface 115, the outer surface has an airfoil shape which changes upon inflating or deflating the cavity 119.

[0056] The rotor blade 100 further comprises in a rear section of the rotor blade, a vortex generator 125 which is arranged in the air flow direction 127 downstream the adaptable spoiler 150. Depending on the state of the adaptable spoiler 150, the effect of the vortex generator 125 on the air flow 127 is changed.

[0057] FIGS. 2 and 3 schematically illustrate in a sectional view as seen when viewed along the longitudinal direction 201 of the rotor blade, a rotor blade 200 according to an embodiment of the present invention including an adaptable spoiler 250 according to an embodiment of the present invention, in two spoiler states. Namely, in FIG. 2, the spoiler 250 is in a fully extended state, where in FIG. 3 the spoiler 250 is in a fully retracted state.

[0058] The embodiment 250 of the spoiler illustrated in FIGS. 2 and 3 are similar to the spoiler 150 illustrated in FIG. 1, also comprising a flexible body 213 having an outer surface 215 and an internal surface 217 limiting a cavity 219. However, different from the embodiment illustrated in FIG. 1, the spoiler 250 illustrated in FIGS. 2 and 3, comprises at least one stiff element 229 which is distinct from the body 213 and has a surface 231 exposed to the air flow 227. The stiff element 229 is attached to the body 213 such that a protrusion height ha, hb and/or tilt angle α of the surface 231 changes upon inflating the cavity 219 to different degree. The stiff element 229 may have the form of a plate, for example plane plate or curved plate, for example having an airfoil shape. When the cavity 219 is deflated, the protrusion height decreases from the height “ha” to the height “hb” and the tilt angle α decreases substantially to zero.

[0059] FIGS. 4 and 5 schematically illustrate in a sectional view a rotor blade 300 according to a further embodiment of the present invention comprising an adaptable spoiler 350 according to another embodiment of the present invention which is further illustrated in a sectional side view when viewed along the longitudinal direction 301 in FIG. 6 in a disassembled configuration.

[0060] The adaptable spoiler 350 comprises a stiff connection structure 333 which is adapted to be connected at a rotor blade surface 305 of the rotor blade 300 having a body 303. The body 313 of the spoiler 350 is coupled to the connection structure 333 and is therefore also mounted at the rotor blade surface 305. The connection structure 333 comprises an upper engagement portion 335 and a lower engagement portion 337 which form a slit 339 between them as can be seen in FIG. 6 illustrating the adaptable spoiler 350 when the stiff connection structure 333 and the body 313 are disassembled. The body comprises an engageable portion 341 configured to be engaged by the upper and lower engagement portions 335, 337 of the stiff connection structure 333, in particular by inserting into the slit 339 and latching within the slit by at least one notch 343 with at least protruding element 345 which may be attached at ends of the upper engagement portion and the lower engagement portion 335, 337.

[0061] FIG. 4 illustrates the fully extended state of the spoiler 350 having a protrusion height ha and a tilt angle α being between e.g. 30° and 90°. FIG. 5 illustrates the retracted state of the spoiler 350 having a protrusion height hb and a tilt angle substantially zero. As can be taken from FIGS. 4 and 5 for example, the outer surface 315 to be exposed to air flow 327 and the internal surface 317 limiting the cavity 319 is arranged in the air flow direction 327 downstream the engageable portion 341 of the body 313.

[0062] FIGS. 7 to 9 schematically illustrate a further embodiment 400 of a rotor blade including an adaptable spoiler 450 additionally providing vortex generating capability. The adaptable spoiler 450 is illustrated in FIGS. 7, 8 and 9 in different states. The spoiler 450 comprises, besides the cavity 419 limited by the internal surface 417 of a body 413, a further internal surface 418 limiting a further cavity 420 to be inflated with fluid to a different level for further adapting the spoiler 450 to different aerodynamic properties. As can be seen from FIGS. 7 to 9, the further internal surface 418 is arranged within the body 413 in a flow direction 427 downstream the internal surface 417.

[0063] The adaptable spoiler 450 further comprises a vortex generator 447 which is formed at the body 413, in particular made from a rigid material and is to be exposed to the air flow 427. Upon inflating the cavity 419 and/or the further cavity 420 to a different degree, the aerodynamic properties of the vortex generator 447 change.

[0064] FIG. 7 illustrates a situation in which the cavity 419 as well as the further cavity 420 are fully deflated such that the vortex generator 447 is entirely exposed to the air flow 427. FIG. 8 illustrates the situation in which the cavity 419 is fully inflated, while the further cavity 420 is fully deflated. In this situation, the vortex generator 447 is almost completely in a wind shadow along the flow direction 427 generated by the inflated cavity 419 causing the outer surface 415 of the body 413 to significantly protrude upwards, such that the vortex generator 447 is essentially in a wind shadow behind the outer surface 415. FIG. 9 illustrates the situation in which both, the cavity as well as the further cavity 420 are fully inflated. In this situation, the vortex generator 447 again is fully exposed to the air flow 427.

[0065] Briefly, FIG. 1 shows a single extruded flexible element; FIGS. 2 and 3 illustrate continuous extruded flexible element with a co-extruded stiff plate for air deflection; FIGS. 4 to 6 illustrate a double piece one continuous extruded flexible section including spoiler, one stiff piece for mechanical connection to blade in particular having a length of 30-50 cm each; FIGS. 7 to 9 illustrate a continuous extruded flexible element with multiple chambers to attain different spoiler configurations.

[0066] The continuous flexible element (also referred to as flexible body) may for example be extruded based on materials such as silicone, TPE, TPU, or similar. The stiff element (for example stiff element 229 illustrated in FIGS. 2, 3 or connection structure 333 illustrated in FIGS. 4 to 6) may be co-extruded with compatible polymer combination, for example a TPE-PP combinations. Stiff elements may be segmented into single pieces of for example 30-50 cm of length. Flexible elements may cover the total extension of the spoiler section.

[0067] Any stiff element may comprise a composite comprising: a fibre material and thermoplastic and/or thermosetting material, the fibre material in particular comprising at least one of: glass fibre and/or carbon fibre and/or Kevlar and/or natural fibre, the thermosetting material in particular comprising at least one of: epoxy, polyester, vinyl ester, resins. The thermoplastic materials comprising at least one of: PP, SAN, ASA, POM, PVC, PE, or any other common thermoplastic material. Any stiff element can comprise also a combination of thermoplastic and fiber reinforced thermoset materials, or fiber reinforced thermoplastics and thermoplastics, or combinations of fiber-reinforced thermoplastics and elastomers, or any other suitable combination thereof.

[0068] Although the present invention has been disclosed in the form of preferred 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.

[0069] 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.