WO2014198353A1

WO2014198353A1 - Rotor blade and vortex generator

Info

Publication number: WO2014198353A1
Application number: PCT/EP2014/000581
Authority: WO
Inventors: Bert Gollnick; Tilman RICHERS; Jens Kulenkampff; Marc Petsche
Original assignee: Senvion Se
Priority date: 2013-06-10
Filing date: 2014-03-06
Publication date: 2014-12-18
Also published as: DE102013210733B4; DE102013210733A1

Abstract

The invention relates to a rotor blade (10) for a wind power plant having a vane (20) arranged on a surface (12) of the rotor blade (10) for influencing an air flow on the surface (12) of the rotor blade (10). A rotor blade according to one embodiment of the invention is further designed such that the vane (20) has a variable effective aerodynamic cross-sectional area, based on an inflow direction of the vane (20) during proper flow (30) around the rotor blade (10). A rotor blade (10) according to an additional embodiment of the invention is further designed such that the vane (20) has a cross section (28, 28') which corresponds to an aerodynamic profile (50). The invention further relates to a vortex generator (40, 40') for a rotor blade (10) of a wind power plant, comprising a vane (20) which, during proper use of the vortex generator (40, 40'), is or becomes arranged on a surface (12) of the rotor blade (10). A vortex generator (40, 40') according to an embodiment of the invention is further designed such that the vortex generator (40, 40') is designed for a modification of an effective aerodynamic cross-sectional area of the vane (20) based on an inflow direction (30) of a rotor blade (10), around which flow properly occurs, by the properly used vortex generator (40, 40'). A vortex generator (40, 40') according to an additional embodiment of the invention is further designed such that the vane (20) has a cross-section (28, 28') which corresponds to an aerodynamic profile (50).

Description

Rotor blade and vortex generator description

The invention relates to a rotor blade for a wind energy plant with a wing arranged on a surface of the rotor blade for influencing an air flow on the surface of the rotor blade.

The invention further relates to a vortex generator for a rotor blade of a wind energy plant comprising a wing, which is or will be arranged on a surface of the rotor blade when the vortex generator is used as intended.

In wind turbines, it is known to increase the buoyancy of a rotor blade to provide the rotor blade with wings, which often have a triangular basic shape and are mounted upright on a surface of the rotor blade. When the rotor blade flows around, each blade generates a near-surface vortex, a so-called vortex. These vortices prevent the formation of an excessively thick turbulent boundary layer between the

CONFIRMATION COPY Surface of the rotor blade and the rotor blade flowing around laminar air flow, whereby a tearing off or detachment of the laminar flow from the rotor blade suppressed and higher buoyancy forces are exerted on the rotor blade. Under a wing is understood in the context of the invention, the part of a vortex generator, which generates a vortex in interaction with the air flowing around the wing. Under wing is understood in particular a vortex-generating sheet.

Due to the higher buoyancy, the energy yield of the wind energy plant can thereby be increased, in particular at wind speeds below the rated wind speed.

On the other hand, at wind speeds above the nominal wind speed, i. E. in operating areas in which the wind turbine is usually controlled or regulated by changing the angle of attack on rated power, to the fact that increased structural loads of the rotor blade and the wind turbine occur because, for example, due to the increased buoyancy and air resistance of the rotor blade through the wind turbine wind turbine with unfavorable Anstellwinkeln must be operated.

The object of the present invention is to improve the aerodynamic properties of a rotor blade of a wind power plant in such a way that the structural loads, in particular at wind speeds above the rated wind speed, are reduced while the energy yield remains constant.

This object is achieved by a rotor blade for a wind energy plant with a wind turbine arranged on a surface of the rotor blade. Neten wing for influencing an air flow on the surface of the rotor blade, wherein the wing, based on a direction of flow of the wing at a designated flow around the rotor blade, a variable effective aerodynamic cross-sectional area.

The invention provides a large effective aerodynamic cross-sectional area of the blade at a low flow velocity, such as prevailing at wind speeds below the rated wind speed of the wind turbine, so that the wing advantageously produces high turbulence or vortex, thereby increasing the buoyancy of the rotor blade and thus the energy yield of the wind turbine is improved.

At the same time, the invention makes it possible to modify, in particular reduce, the effective aerodynamic cross-sectional area of the wing, in the case of high wind speeds, in particular above the rated wind speed. This reduces the swirling or vortexing of the wing, thereby reducing structural stresses on the rotor blade and / or the wind turbine.

At the same time, a smaller effective aerodynamic cross-sectional area means less air resistance, so that the invention also allows a variation of the contribution from the wing to the air resistance of the entire rotor blade and, within certain limits, the change in the quotient of lift and air resistance.

As a result, the invention provides additional operating configurations with improved energy efficiency for the operation of a wind energy plant. yield with simultaneously lower structural load available.

For the purposes of the invention, the effective aerodynamic cross-sectional area is understood to be, in particular, the projected cross-sectional area which the wing of the air intended for the purpose of opposing the rotor blade opposes.

An advantageous embodiment of the invention is characterized in that the wing to change its effective aerodynamic cross-sectional area about an axis of rotation, which is aligned in particular transversely to the surface of the rotor blade, rotatable and / or about a pivot axis which is aligned in particular along the surface of the rotor blade is pivotally configured, wherein the effective aerodynamic cross-sectional area of the wing in a first rotational or pivotal position is greater than the effective aerodynamic cross-sectional area of the wing in a second rotational or pivotal position.

The first rotational or pivotal position is particularly characterized in that the wing in this position provides an optimal or maximum or maximum contribution to the buoyancy of the rotor blade, whereas the second rotational or pivotal position is particularly characterized in that the wing in this position a particularly makes a small contribution to the buoyancy of the rotor blade, which in particular can be zero or negative. In this context, the contribution of the wing to the buoyancy of the rotor blade is understood in particular to be the difference between the buoyancy of the rotor blade and the wing in the respective turning or pivoting position on the one hand and the buoyancy of a comparable rotor blade without wings under identical inflow conditions on the other hand. In particular, the wing has a transverse direction which is excellent in that the dimension or dimension of the wing along the transverse direction is minimal in comparison with all other directions. The orientation of the wing is specified in the context of the invention by means of a wing main plane, which is particularly characterized in that it is aligned perpendicular to the transverse direction of the wing.

An angle between the direction of flow of the wing and the wing main plane is referred to below as the angle of rotation of the wing. An angle between the wing main plane and the surface of the rotor blade is referred to below as the swing angle of the wing.

In the first rotational or pivoting position, the main plane of the wing is preferably arranged transversely to the surface of the rotor blade for the largest possible effective aerodynamic cross-sectional area of the wing, for example with a pivoting angle of about 90 °.

At the same time, the main plane of the wing in the first rotational or pivoting position is preferably oriented obliquely to the inflow direction of the air flowing around the rotor blade, the sign of the rotational angle influencing the vortex direction of the generated vortex.

The second rotational or pivotal position of the wing, which is particularly characterized in that the wing in the second rotational or pivotal position has a smaller effective aerodynamic cross-sectional area than in the first rotational or pivotal position, in particular has a relation to the first rotary or Swivel position smaller angle of rotation and / or smaller swivel angle.

The effective aerodynamic cross-sectional area of the wing is reduced in particular by the fact that the wing is pivoted toward the surface of the rotor blade and / or ged to the direction of flow of the air flowing around the rotor blade.

Expressly embraced by the invention are those embodiments in which the wing between the first rotational or pivotal position and the second rotational or pivotal position performs a movement corresponding to a superposition of a rotational movement and a pivoting movement.

Advantageously, the wing is arranged on the rotor blade, that acts due to a proper flow around the rotor blade, an aerodynamic force on the wing, the at least one sub-component in the direction of a rotary or pivotal movement of the wing from the first rotational or pivotal position in the second rotary or Has pivoting position.

Advantageously, in the absence of the aerodynamic force, the wing assumes the first turning or pivoting position, which is achieved for example by suitably balanced bearing of the wing, suitable counterweights or by means of a return device for the wing.

As a result, in particular a mechanical, passive construction is made possible, in which the acting aerodynamic forces are used as a drive for the movement of the wing and controlled by predetermined opposing forces. This construction is in the Easy and cost-effective position, reliable and low-maintenance during operation.

A particularly advantageous embodiment of the invention is characterized in that the wing located in the first rotary or pivoting position remains there until an aerodynamic force acting on the wing under normal flow around the rotor blade is greater than a, in particular predeterminable, first threshold force. For this purpose, the rotor blade comprises, for example, a suitable holding device for the wing. Instead of the force may also be present a corresponding torque that is greater than a torque limit to bring the wing in a second rotational or pivotal position.

This ensures that the wing remains in the interest of optimum energy yield in the first rotational or pivotal position, as long as the structural loads of the rotor blade or the wind turbine despite the contribution of the wing to buoyancy and air resistance of the rotor blade in an acceptable range.

It is also advantageous if the wing located in the second rotational or pivoting position remains there until an aerodynamic force acting on the wing during intended flow around the rotor blade is smaller than a, in particular predeterminable, second force threshold.

This prevents the wing from leaving the second rotational or pivotal position, thereby potentially increasing the effective aerodynamic cross-sectional area, as long as the associated change in buoyancy and drag of the rotor blade result in undesirably high aerodynamic and / or can cause structural loads on the rotor blade and / or the wind turbine.

Preferably, the rotor blade according to the invention is designed such that in a first flow around the rotor blade, in which acting in the first rotational or pivotal position on the wing aerodynamic force is greater than the first force threshold, in the second rotational or pivotal position on the wing acting aerodynamic force is greater than the second force threshold and that in a second flow around the rotor blade, wherein the force acting in the second rotational or pivotal position on the wing aerodynamic force is smaller than the second force threshold, in the first rotational or pivotal position on the aerodynamic force acting on the wing is smaller than the first force threshold.

This ensures that the wing is always either in the first rotational or pivotal position or in the second rotational or pivotal position and thus states with uncontrollable effects on the aerodynamics of the wing and / or the rotor blade can be avoided.

Advantageously, the first force threshold and the second force threshold are further coordinated so that there is a transition region for the flow or wind speed, in which the wing remains in its position, regardless of whether it is in the first rotational or pivotal position or in the second rotational or pivotal position is. This prevents the wing constantly changes from a rotational or pivotal position in the other rotational or pivotal position in turbulent wind conditions or changing flow around. The turning or pivoting behavior is preferably provided with a hysteresis. In a further advantageous embodiment of the invention, it is provided that the wing is at least partially deformable to change its effective aerodynamic cross-sectional area, so that deforms the wing in response to a force acting on the wing under proper flow of the rotor blade aerodynamic force, in particular the effective aerodynamic cross-sectional area of the wing in an undeformed state is greater than the effective aerodynamic cross-sectional area of the wing in a deformed state.

By deformation comparable effects can be achieved as by means of the described rotation and / or pivoting of the wing. In particular, the wing can, in a suitable embodiment, twist comparable to a rotation and / or bend laterally comparable to a pivoting.

By suitable choice of material and suitable arrangement of flexible and rigid sections, a wide range of blades with different deformation properties is provided, from which the embodiment optimized for the individual case can be suitably used.

In addition, the deformation takes place in particular continuously as a function of the applied force, so that sudden changes in the effective aerodynamic cross-sectional area of the wing are prevented. This prevents in particular that due to sudden change in the buoyancy or the air resistance of a rotor blade according to the invention short-term peaks occur in the structural load. Furthermore, flexible wings are in particular resistant to external mechanical influences, such as may occur, for example, during icing of the rotor blade or in the case of improper handling during transport and installation of the rotor blade. As a result, the life of the wings is increased and improves the efficiency of the wind turbine.

The object underlying the invention is further achieved by a rotor blade for a wind turbine with a arranged on a surface of the rotor blade for influencing an air flow on the surface of the rotor blade, which is in particular a rotor blade according to one of the embodiments of the invention already described, wherein the Wing has a cross section corresponding to an aerodynamic profile, in particular an asymmetric aerodynamic profile with straight pressure side and curved suction side.

The inventive design of the wing with an aerodynamic profile causes a reduction in the air resistance of the wing and thus also a reduction in the air resistance of the rotor blade and thus also contributes to a reduction of the structural load of the rotor blade.

At the same time, the strength of a vortex or vortex generated by the wing is increased by the aerodynamic profile of the wing and thus the buoyancy of the rotor blade, so that a comparable energy yield at lower angles of attack of the rotor blade and thus lesser structural load of the rotor blade are made possible.

Furthermore, the inventive design of the wing with an aerodynamic profile surprisingly causes an ne improvement in other problems in the prior art.

As a rule, the wings or winglets of known wind power plants are not mechanically loadable, in particular because they are designed to be relatively thin at least in sections in the interests of aerodynamic properties. The reinforcement of these weak points by more material deteriorates the aerodynamic properties and the performance and yield increases desired, so that usually an increased maintenance and repair costs for defective or functionally impaired wings is accepted.

Compared to this prior art, the invention substantially improves the mechanical stability of the wing, while maintaining or improving the desired aerodynamic characteristics of the wing.

The object underlying the invention is further achieved by a vortex generator for a rotor blade of a wind turbine, in particular for a rotor blade according to the invention described above, comprising a wing, which is or will be arranged on intended use of the vortex generator on a surface of the rotor blade, wherein the vortex generator is formed , To change an effective aerodynamic cross-sectional area of the wing with respect to a direction of flow of a designated purpose flow around the rotor blade with the vortex generator used as intended or provide changeable.

The vortex generator is designed in particular as a component or replacement part for a rotor blade of a wind energy plant, in particular for a previously described inventive rotor blade or for a rotor blade, which together with the vortex generator Having described features of the invention.

The vortex generator in a first variant of the invention comprises a fastening device for fastening the wing to the rotor blade, wherein the fastening device for a rotation of the wing about an axis of rotation, which is aimed at the intended use of the fastening device, in particular transversely to the surface of the rotor blade, and / or a pivoting of the wing about a pivot axis, which is aligned in accordance with the intended use of the vortex generator, in particular along the surface of the rotor blade is formed, wherein at least a first rotational or pivotal position and a second rotational or pivotal position are provided for the wing.

In particular, the first rotational or pivot position for a comparatively large effective aerodynamic cross-sectional area of the wing and the second rotational or pivotal movement for a comparatively small effective aerodynamic cross-sectional area of the wing is formed, wherein the terms comparatively large and comparatively small in particular to a comparison of different rotation - or pivot positions of the same wing relate.

Preferably, the vortex generator comprises a first holding device for the wing, which holds the wing located in the first rotational or pivot position there, until an acting on the wing in the direction of the second rotational or pivotal external force is greater than a predetermined first force threshold.

The external force is, in particular, a vortex generator used for the intended flow around a rotor blade with the intended use of the vortex generator or for the intended use. tion of the vortex generator acting aerodynamic force, in particular a component of this aerodynamic force in the direction of the second rotational or pivotal position.

Advantageously, the vortex generator comprises a second holding device for the wing, which holds the wing located in the second rotational or pivot position there, as long as an external force acting on the wing from the direction of the first rotational or pivotal position is smaller than a predetermined second force threshold.

Particularly preferred embodiments of a vortex generator according to the invention comprise both a first and a second holding device. It can also be provided an embodiment of the invention, in which the first and the second holding device are realized in a single holding device. Furthermore, a variant is conceivable in which only a second holding device is realized.

The vortex generator preferably comprises a restoring device for returning the wing to the first turning or pivoting position. This ensures that the wing returns to the first rotational or pivotal position as soon as the external force acting on the wing, and thus in particular the instantaneous wind condition, permits this.

In addition, a Rückstelivorrichtung ensures a suitable design, a smooth movement of the wing between the first rotational or pivotal position and second rotational or pivotal position, which damped chaotic, erratic or oscillating movements of the wing with corresponding undesirable changes in its aerodynamic properties or prevented.

Advantageous embodiments of the invention are characterized in that the first holding device and / or the second holding device and / or the rear part device comprises a magnet and / or a spring and / or a system with at least two releasably connectable connecting elements.

In particular, the first holding device and / or the second holding device and / or the restoring device comprise action means for acting on the wing with a holding or restoring force. In addition to active agents with remote action, for example based on electrical or magnetic fields and forces, these can also be active agents without remote action. The latter include, in particular, mechanical solutions, for example detachable fastening systems with form-locking or force-locking interlocking fastening elements, as well as detachable adhesive bonds.

In further embodiments of the invention, the vortex generator according to the invention comprises a positioning device with an actuator for the wing, which brings the wing in a, in particular via control commands predeterminable, rotational or pivotal position and holds there.

In a second variant of the invention, it is provided that the wing of the vortex generator is deformable at least in sections so that the wing arranged as intended on the rotor blade deforms as a function of an external force acting on the wing.

Preferably, the wing deforms in principle elastic, the wing after completion of the force in its original jump form returns.

Advantageously, the wing is at least partially designed to plastically deform as soon as an external force acting on the wing exceeds a predetermined safety force threshold.

As a result, under extreme wind conditions and correspondingly very high external forces acting on the wing, the comparatively simple and cost-effective vortex generator to be replaced is first of all impaired or destroyed, before critical or supercritical peak loads on the rotor blade or the wind energy installation occur under certain circumstances.

Such a predetermined bending point has in particular the advantage over a predetermined breaking point that, in addition, a risk of injury in the surroundings of the wind energy plant is avoided by detached vortex generators or wings.

Preferably, the change in the effective aerodynamic cross-sectional area of the blade is coupled to a torsion of the rotor blade. For example, it can be provided for this purpose that the surface of the rotor blade on which a vortex generator is mounted or the attachment device of the vortex generator deforms with a corresponding torsion of the rotor blade, so that due to the deformation of a force on the wing or a position of the wing changing Device is exercised so that the position of the wing or the position of the wing changes. In this case, preferably at least two metastable layers of the wing are provided. For example, a snapped-in position and a snapped-off position can be provided. The object underlying the invention is also achieved by a vortex generator for a rotor blade of a wind turbine, in particular for a rotor blade according to the invention described above, comprising a wing, which is or is arranged at the intended use of the vortex generator on a surface of the rotor blade, wherein the wing has a cross section which corresponds to an aerodynamic profile, in particular an asymmetrical aerodynamic profile with a straight pressure side and a curved suction side.

Preferably, the vortex generator additionally has one or more of the features according to the invention already described.

Preferably, a rotor blade according to the invention comprises a vortex generator according to the invention, wherein in particular the blade of the rotor blade or the wing, which is arranged on the rotor blade, is a wing of the vortex generator.

Further features of the invention will become apparent from the description of embodiments according to the invention together with the claims and the accompanying drawings. Embodiments of the invention may satisfy individual features or a combination of several features.

The invention will be described below without limiting the general inventive idea by means of embodiments with reference to the drawings, reference being expressly made to the drawings with respect to all in the text unspecified details of the invention. Show it:

Fig. 1 shows schematically a portion of an inventive

Rotor blade with wings; FIG. 2 schematically shows a plan view of a vortex generator according to the invention according to a first embodiment of the invention; FIG.

FIG. 3a schematically shows a sectional view along the line A - A from FIG. 2; FIG.

FIG. 3b schematically shows an enlarged partial view of the sectional view from FIG. 3a;

Fig. 4 is a schematic sectional view taken along the line B-B of Fig. 2;

Fig. 5 is a schematic side view of a vortex generator according to the invention according to another embodiment of the invention;

Fig. 6 shows schematically a plan view of an inventive

Vortex generator according to another embodiment of the invention;

Fig. 7a shows schematically a top view of a device according to the invention

Vortex generator according to another embodiment of the invention; and

7b schematically shows a perspective view of the wing of the vortex generator according to the invention from FIG. 7a.

In the drawings, the same or similar elements and / or parts are provided with the same reference numerals, so that of a renewed presentation is omitted in each case.

FIG. 1 schematically shows a section of a rotor blade 10 according to the invention in a perspective view. The rotor blade 10 has a cross section with an aerodynamic profile 14 and has a pressure side 15 and a suction side 16.

On the suction side 16 of the rotor blade 1 0 12 small wings 20 are arranged on the rotor blade surface. The wings 20 have a triangular basic shape and are up to 140 mm long and 35 to 70 mm high.

The rotor blade 10 is intended to flow against the rotor blade nose 17, as shown schematically by the arrow 30. In this case, the rotor blade 1 0 flows around from the rotor blade nose 17 to the rotor blade trailing edge 18.

If the wings 20 as shown in FIG. 1, transverse to the rotor blade surface 12 and aligned obliquely to the direction of flow 30, is formed downstream of each wing 20, a vortex or vortex, the orientation of a wing 20 to the direction 30 indicates the direction of rotation of the respective vortex. The orientation of the wings 20 is preferably as shown in FIG. 1 alternately so that adjacent vortices have opposite directions of rotation.

The strength of a vortex depends on the effective aerodynamic cross-sectional area of the respective wing 20, which approximately corresponds to the projected cross-sectional area which the wing 20 opposes to the inflowing air.

The vanes 20 of the rotor blade 10 are, for example, part of a vortex generator 40, 40 'which is fastened to the rotor blade 10 is.

According to a first variant of the invention, the effective aerodynamic cross-sectional area is designed to be variable, in particular to adapt the aerodynamic effect of the wing to different wind conditions, in particular different wind speeds.

FIG. 2 schematically shows a plan view of a vortex generator 40 according to a first embodiment of the invention. Schematic cross-sectional views of the vortex generator 40 of FIG. 2 taken along the line A-A are shown in FIGS. 3a and 3b, and FIG. 4 is a schematic sectional view of the vortex generator 40 of FIG. 2 taken along the line B-B.

The vortex generator 40 comprises a base plate 42 and vanes 20 movably mounted to the base plate 42, the vanes 20 being shown in a first wing position 22 in solid lines and the wings 20 in a second wing position 24 in broken lines. When used as intended, the vortex generator 40 is attached to a rotor blade 10, in particular the top of the base plate 42, i. the side of the base plate 42, on which the wings 20 are arranged, is or becomes part of the rotor blade surface 12.

In the first wing position 22, the wings 20 are aligned transversely to the base plate 42 and the rotor blade surface 12 and in particular stand upright on the base plate 42. Thus, the wings 20 in the first position 22 has a relatively large effective aerodynamic cross-sectional area and generate correspondingly strong vortex. In the second wing position 24, the wings 20 are aligned along the base plate 42 and lie in particular flat over the base plate 42. As a result, the wings 20 in the second position 24 has a comparatively small effective aerodynamic cross-sectional area, because in particular the projection of the wings 20 in the direction of flow 30th in the second position 24 is much flatter than in the first position 22.

In the sectional illustration of FIG. 3 a, it is shown that the vortex generator 40 comprises a mounting base 44 fastened to the base plate 42 or formed as part of the base plate 42 for a wing 20.

In a comparable embodiment, a mounting base 44 serves for fastening a vortex generator according to the invention to a rotor blade 10, wherein this vortex generator in particular has no base plate 42. In a further comparable embodiment, a rotor blade 10 according to the invention has a corresponding mounting base 44 for a wing 20.

In Fig. 3b is an enlarged view of the sectional view of Fig. 3b shown with further details. The wing 20 is connected by means of a pivot bearing 46 with the mounting base 44, whereby a pivoting of the wing 20 from the first position 22 in the second wing position 24 and vice versa is made possible.

On the pivot bearing 46, a Rückstellvorrich- not shown, which is formed for example as a return spring, provided, which acts on the wing 20 with a restoring force in the direction of the first wing position 22. The restoring force is preferably provided sufficiently large to overcome the forces acting on the wing 20 mass forces. This will take the wing 20 in each position of the vortex generator 40 and the corresponding rotor blade 10, the first wing position 22, if no other forces, in particular aerodynamic forces acting on the wing 20.

Furthermore, a first magnet 48 is provided, which acts on the wing 20 in the first wing position 22 with a holding force. The first magnet 48 is arranged, for example, on the mounting base 44, the wing 20 in this case having a ferromagnetic material.

The first magnet 48 is, for example, a permanent magnet, which can in particular provide a maximum holding force for acting on the wing 20 in the first wing position 22. If this maximum holding force is overcome by an external force acting on the wing 20, for example an aerodynamic force, the magnet 48 can no longer hold the wing 20 in the first wing position 22 and the wing pivots or tilts into the second wing position 24. As a result In particular, a first force threshold is provided for an external force, wherein the wing 20 located in the first wing position 22 remains there until the external force exceeds the force threshold.

The magnet 48 may for example also be designed as an electromagnet. In this case, an active control is possible, wherein the strength of the magnet 48 and thus the force threshold is changed for example on the basis of sensor data or measured values. In this case, the sensor data relate, for example, to a mechanical load on the vortex generator 40 and / or the prevailing wind and flow conditions. The sensor data or measured values preferably relate to a torsion of the rotor blade, so that, depending on the torsion of the rotor blade, a vane position on is specifiable.

The first wing position 22 is in particular aligned so that the wing 20 swirls the incoming air 30 as intended. As a result, aerodynamic forces act on the wing 20 in the first wing position 22, which in particular have a force component in the direction of the movement possibility of the wing 20 toward the second wing position 24. As this force or force component overcomes the holding force of the magnet 48 or an alternative fixture, the wing 20 moves from the first wing position 22 toward the second wing position 24. This reduces the effective aerodynamic cross-sectional area of the wing 20, thereby reducing both the strength of the vortex generated as well as the aerodynamic forces acting on the wing decrease.

The pivot axis 47 of the wing, which is predetermined in particular by the orientation of the pivot bearing 46 (see FIG. 3 b), is preferably oriented slightly inclined relative to the base plate 42 or to the rotor blade surface 12, as shown in FIG. 4. This gives the wing 20 in the second wing position 24, in which the strength of the vortex is usually to be as low as possible and correspondingly low aerodynamic forces acting on the wing 20, a small negative angle of attack towards the flow direction 30. Even with laminar flow around the wing 20, d. H . without whirling, it is thus ensured that an output force acts on the wing 20. This ensures that the wing 20 moves to the second wing position 24 after leaving the first wing position 22. In addition, it is prevented that there are undesirable labile or metastable equilibrium positions for the wing 20 between the first wing position 22 and the second wing position 24. The inclination of the pivot axis 27 and thereby predetermined angle of attack of the wing 20 in the second wing position 24 determine a minimum flow velocity, above which the output force optionally overcomes the wing 20 acting on restoring force and the wing 20 thus remains in the second wing position 24. In this way, a second force threshold for an external force acting on the wing 20 force, in particular an aerodynamic force as the output force described, given.

In order to predetermine or determine this force threshold, as shown in FIG. 3 b, a second magnet 48 'may be provided for holding the wing 20 in the second wing position 24. As a result, the wing 20 is acted upon in the second wing position 24 with a further force component that can be easily and accurately specified by appropriate specification of the magnetic field strength. This opens up for the interpretation of the respective embodiment of the invention, a further creative degree of freedom, which can be used, for example, to optimize the reliability. For example, the inclination of the pivot axis 27 can be designed for minimized air resistance of the wing 20 in the second wing position 24, wherein the magnet 28 is suitably selected to specify the second force threshold.

In the context of the invention, other arrangements of the magnets 48, 48 'are possible, for example on the wing 20 instead of the mounting base.

Furthermore, within the scope of the invention, the magnets 48, 48 'can also be replaced by suitable alternative holding devices with active means for applying a holding force to the wing. In addition to active agents with remote action, for example the described magnets 48, 48 ', these can also be active agents without remote action. The latter include, for example, releasable fastening systems with positive or non-positive intermeshing fastening elements and detachable adhesive joints.

Fig. 5 shows schematically the side view of a wing 20 of a further embodiment of the invention. The vane 20 is rigidly connected to the base plate 42 of a vortex generator 40, wherein alternative rigid attachments to a vortex generator 40 or a rotor blade 10 are according to the invention.

The wing 20 has a flexible region 26 near the attachment. This is realized for example by a suitable material or a suitable shaping of the wing 20.

When the blade engages an external force transverse to its surface, such as when properly used to create a vortex, the wing 20 is deformed in the flexible region 26, the orientation and shape of the flexible region 26 dictating how large and in which The wing 20 and the flexible portion 26 of the wing 20 is deformed depending on the applied force. In particular, there is a continuous balance between the size and type of deformation on the one hand and the strength of the force acting on the wing 20 force.

The elongate flexible region 26 shown in FIG. 5, for example, causes a tilting movement of the wing 20, which corresponds to the pivoting movement of the previously described embodiment of the invention. In this case, the flexible portion 26 is deformed more and more with increasing tilt angle, which requires correspondingly increasingly strong external forces. At the same time reduced by the tilting movement in the proper use of the blade to form vortices the effective aerodynamic cross-sectional area of the wing 20, so that the aerodynamic forces acting on the wing 20 decrease with increasing tilt angle. In this way, always establishes an equilibrium position of the wing 20 with a dependent of the flow velocity tilt angle.

By suitable configuration of the shape and position of the flexible region 26 in the wing 20 and the flexibility of the flexible region decisively determined by shape and material, the deformation behavior of the wing 20 can be predetermined in many different ways and can be adapted and optimized for the respective embodiment of the invention in individual cases. Variations within the scope of the invention are, in particular, wings 20, in which the flexible region 26 essentially corresponds to the entire wing 20.

FIG. 6 shows schematically the plan view of a vortex generator 40 'according to a further embodiment of the invention, which is of the kind shown in FIG. 2 corresponds.

The vortex generator 40 'comprises a base plate 42 and two transverse to the base plate aligned wings 20. The wings 20 are rotatably supported by means of a respective pivot bearing 49, which is aligned in particular transversely to the base plate 42. The pivot bearing 49 is in each case arranged in front of the aerodynamic center of gravity of the wing 20, so that in the illustrated inflow direction 30 of the wing 20 under the action of an aerodynamic force in the so-called feathering position, in which the wing 20 is aligned in particular longitudinal to the flow direction 30, rotates.

In each case, an unillustrated reset element is advantageously provided. Device provided for the wings 20, which acts on the wing 20 with a counteracting the aerodynamic force restoring force. It is also conceivable to couple the counter-rotating vanes 20 in pairs by means of a rear-part device comprising, for example, a spring.

In the previously described embodiments of the invention, the movement of a wing 20 was carried out in each case due to a force acting externally on the wing, in particular a force occurring when the wing 20 is used as intended, aerodynamic force. However, embodiments which comprise an actuator for moving a wing 20 are also encompassed by the invention. In this way, an active control of the aerodynamic properties of the wing 20 and thus of the rotor blade 10, on the surface 12 of the wing 20 is arranged according to the invention, allows.

According to a second variant of the invention, the wings 20 of a rotor blade 10 according to the invention or of a vortex generator 40, 40 'according to the invention have a cross-sectional area 28, 28' which corresponds to an aerodynamic profile 50. A wing 20 according to this variant is shown in FIGS. 7a and 7b, wherein FIG. 7a shows a perspective illustration and FIG. 7b shows a schematic plan view of the wing 20 according to the invention.

The wing has a base surface or cross-sectional area 28 at its base. For the purpose of producing a vortex or Vortexes the wing 20 is oriented such that the base surface or cross-sectional surface 28 of the surface 12 of a rotor blade 10 faces and that the wing 20 is flowed in accordance with the intended flow around the rotor blade obliquely from the indicated by the arrow flow direction 30 , The cross-sectional area 28 has the shape of an aerodynamic profile 50 or corresponds to an aerodynamic profile 50. The aerodynamic profile 50 is in particular asymmetrical with a straight pressure side 52 and a convexly curved or curved suction side 54.

In order to clarify the three-dimensional shape of the wing 20, the cross-sectional area 28 'at half the height of the wing 20 is additionally shown in dashed lines in FIGS. 7a and 7b. The cross-sectional area 28 'is, for example, similar in shape to the cross-sectional area 28, and thus in particular has the same aerodynamic profile as the cross-sectional area 28. However, also encompassed by the invention are those embodiments in which the aerodynamic profile of the cross-sectional area 28, 28 'of the wing 20 varies with the height of the wing.

All mentioned features, including the drawings alone to be taken as well as individual features that are disclosed in combination with other features are considered alone and in combination as essential to the invention. Embodiments of the invention may be accomplished by individual features or a combination of several features.

LIST OF REFERENCE NUMBERS

1 0 rotor blade

1 2 Rotor blade surface 14 Rotor blade profile

1 5 print page

16 suction side

17 rotor blade nose

1 8 trailing edge

20 wings

22 first wing position 24 second wing position 26 flexible section

28, 28 'cross-sectional area

30 direction of flow

40, 40 'vortex generator

42 base plate

44 Mounting base 46 Swivel bearing

47 pivot axis

48, 48 'magnet

49 pivot bearings

50 aerodynamic profile 52 pressure side

54 suction side

Claims

Rotor blade and vortex generator claims

1 . Rotor blade (10) for a wind energy plant with a wing (20) arranged on a surface (12) of the rotor blade (1 0) for influencing an air flow on the surface (12) of the rotor blade (1 0), wherein the wing (20), has a variable effective aerodynamic cross-sectional area with respect to a direction of flow of the wing (20) when the flow around (30) of the rotor blade (10) is in accordance with the regulations.

2. rotor blade (1 0) according to claim 1, characterized in that the wing (20) for changing its effective aerodynamic cross-sectional area about an axis of rotation (49), in particular transversely to the surface (1 2) of the rotor blade (1 0) aligned is rotatably and / or about a pivot axis (46, 47), which in particular along the surface (12) of the rotor blade (1 0) is aligned pivotally, wherein the effective aerodynamic cross-sectional area of Wing (20) in a first rotational or pivotal position (22) is greater than the effective aerodynamic cross-sectional area of the wing in a second rotational or pivotal position (24).

Rotor blade (1 0) according to claim 2, characterized in that the wing (20) is arranged on the rotor blade (10) that due to a proper flow around (30) of the rotor blade (10) an aerodynamic force acts on the wing (20) comprising at least one sub-component in the direction of pivotal movement of the wing (20) from the first rotational or pivotal position (22) to the second rotational or pivotal position (24), the wing (20) in particular in the absence of the aerodynamic Force the first rotational or pivotal position (22) occupies.

Rotor blade (1 0) according to claim 3, characterized in that in the first rotational or pivotal position (22) located wing (20) remains there until a proper flow around (30) of the rotor blade (10) on the wing (20 ) acting aerodynamic force is greater than a, in particular predeterminable, first force threshold.

Rotor blade (10) according to claim 3 or 4, characterized in that the in the second rotational or pivotal position (24) located wing (20) remains there until a designated flow around (30) of the rotor blade (1 0) on the wing (20) acting aerodynamic force is smaller than a, in particular predeterminable, second force threshold.

Rotor blade (1 0) according to claim 4 and 5, characterized in that in a flow around (30) of the rotor blade (1 0), wherein the aerodynamic force acting on the wing (20) in the first rotational or pivotal position (22) is greater than the first force threshold, the aerodynamic force acting on the wing (20) in the second rotational or pivotal position (24) greater is as the second force threshold and that in a flow around (30) of the rotor blade (1 0), in which in the second rotational or pivotal position (24) acting on the wing (20) aerodynamic force is smaller than the second force threshold in the first rotational or pivotal position (22) on the wing (20) acting aerodynamic force is smaller than the first force threshold.

Rotor blade (10) according to claim 1, characterized in that the wing (20) for changing its effective aerodynamic cross-sectional area is formed at least partially deformable, so that the wing (20) in dependence on an intended flow around (30) of the rotor blade (1 0) deforms on the wing (20) acting aerodynamic force, in particular, the effective aerodynamic cross-sectional area of the wing (20) in an undeformed state is greater than the effective aerodynamic cross-sectional area of the wing (20) in a deformed state.

Rotor blade (1 0) for a wind energy plant with a wing (20) arranged on a surface (12) of the rotor blade (1 0) for influencing an air flow on the surface (12) of the rotor blade (1 0), in particular rotor blade (1 0) according to one of claims 1 to 7, wherein the wing (20) has a cross-section (28, 28 ') which an aerodynamic profile (50), in particular an asymmetrical aerodynamic profile (50) with straight pressure side (52) and curved Suction side (54), corresponds.

Vortex generator (40, 40 ') for a rotor blade (1 0) of a wind energy plant, in particular for a rotor blade (1 0) according to one of claims 1 to 8, comprising a wing (20) which, when the vortex generator (40, 40 ') is arranged on a surface (12) of the rotor blade (1 0) or, wherein the vortex generator (40, 40') is formed, an effective aerodynamic cross-sectional area of the wing (20) with respect to a direction of flow (30) of an intended flow around Rotor blade (1 0) with the intended purpose vortex generator (40, 40 ') to change.

Vortex generator (40, 40 ') according to claim 9, characterized in that the vortex generator (40, 40') comprises a fastening device (42, 44) for fastening the wing (20) to the rotor blade (10), wherein the fastening device (42 , 44) for a rotation of the wing (20) about an axis of rotation (49), which is aligned with the proper use of the fastening device (42, 44) in particular transversely to the surface (12) of the rotor blade (1 0), and / or for a Pivoting of the wing (20) about a pivot axis (46, 47), which is in particular when using the Vortexgenerators (40, 40 ') longitudinally aligned to the surface (1 2) of the rotor blade (1 0) is formed, wherein for the wing (20) at least a first rotational or pivotal position (22) and a second rotary or pivotal position (24) are provided. Vortex generator (40, 40 ') according to claim 1 0, characterized in that the vortex generator (40, 40') has a first Holding device (48, 48 ') for the wing (20) which holds the in the first rotational or pivotal position (22) located there wing (20) until one on the wing (20) in the direction of the second rotary or Swivel position (24) acting external force is greater than a predetermined first force threshold.

Vortex generator (40, 40 ') according to claim 10 or 1 1, characterized in that the vortex generator (40, 40') comprises a second holding device (48, 48 ') for the wing (20), which in the second rotary or swing position (24) located there holds, as long as an on the wing (20) acting external force from the direction of the first rotational or pivotal position (22) is greater than a predetermined second force threshold.

Vortex generator (40, 40 ') according to one of claims 1 to

12, characterized in that the vortex generator (40, 40 ') comprises a return device for resetting the wing (20) in the first rotational or pivotal position (22).

Vortex generator (40, 40 ') according to one of claims 1 1 to

1 3, characterized in that the first holding device (48, 48 ') and / or the second holding device (48, 48') and / or the return device comprises a magnet (48, 48 ') and / or a spring and / or a System comprising at least two releasably connectable connecting elements.

Vortex generator (40, 40 ') according to one of claims 1 1 to 14, characterized in that the vortex generator (40, 40') comprises a positioning device with an actuator for the wing (20), which the wing (20) in a in particular particular via control commands predetermined, rotary or pivotal position (22, 24) brings and holds there.

Vortex generator (40, 40 ') according to claim 9, characterized in that the wing (20) is formed at least partially deformable, so that the intended on the rotor blade (10) arranged wings (20) in dependence of an external force acting on the wing deformed.

Vortex generator (40, 40 ') according to claim 16, characterized in that the wing (20) elastically deformed.

Vortex generator (40, 40 ') according to claim 16 or 1 7, characterized in that the wing (20) is at least partially formed to deform plastically as soon as an external force acting on the wing (20) exceeds a predetermined safety force threshold.

Vortex generator (40, 40 ') according to any one of claims 9 to 18, characterized in that the change in the effective aerodynamic cross-sectional area of the wing (20) with a torsion of the rotor blade (1 0) is coupled.

Vortex generator (40, 40 ') according to claim 1 9, characterized in that at least two metastable layers of the wing (20) are provided.

Vortex generator (40, 40 ') for a rotor blade (1 0) of a wind turbine, in particular Vortexgenerator (40, 40') according to one of claims 9 to 20, in particular for a rotor blade (1 0) according to one of claims 1 to 8, comprising a wing gel (20), which is or will be arranged on a surface (12) of the rotor blade (10) when the preform generator (40, 40 ') is used as intended, the wing (20) having a cross-section (28, 28') which corresponds to an aerodynamic profile (50), in particular an asymmetrical aerodynamic profile (50) with a straight pressure side (52) and a curved suction side (54).

Rotor blade (1 0) according to one of claims 1 to 8 comprising a vortex generator (40, 40 ') according to one of claims 9 to 21, wherein in particular the wing (20) of the rotor blade (1 0) a vane (20) of the vortex generator ( 40, 40 ').