Patent Description:
Wind power is considered one of the cleanest, most environmentally friendly energy sources presently available, and wind turbines have gained increased attention in this regard. A modem wind turbine typically includes a tower, generator, gearbox, nacelle, and one or more rotor blades. The rotor blades capture kinetic energy from wind using known foil principles and transmit the kinetic energy through rotational energy to turn a shaft coupling the rotor blades to a gearbox, or if a gearbox is not used, directly to the generator. The generator then converts the mechanical energy to electrical energy that may be deployed to a utility grid.

Wind turbine rotor blades generally include a body shell formed by two shell halves of a composite laminate material. The shell halves are generally manufactured using molding processes and then coupled together along the corresponding ends of the rotor blade. In general, the body shell is relatively lightweight and has structural properties (e.g., stiffness, buckling resistance, and strength) which are not configured to withstand the bending moments and other loads exerted on the rotor blade during operation.

In recent years, wind turbines for wind power generation have increased in size to achieve improvement in power generation efficiency and to increase the amount of power generation. Along with the increase in size of wind turbines for wind power generation, wind turbine rotor blades have also significantly increased in size (e.g., up to <NUM> meters in length), resulting in difficulties in integral manufacture as well as conveyance and transport of the blades to a site.

In this regard, the industry is developing sectional wind turbine rotor blades wherein separate blade segments are manufactured and transported to a site for assembly into a complete blade (a "jointed" blade). In certain constructions, the blade segments are joined together by a beam structure that extends span-wise from one blade segment into a receiving section of the other blade segment. Reference is made, for example, to <CIT>, which describes a first blade segment with a beam structure extending lengthways that structurally connects with a second blade segment at a receiving section. The beam structure forms a portion of the internal support structure for the blade and includes a shear web connected with a suction side spar cap and a pressure side spar cap. Multiple bolt joints are used to connect the beam structure with the receiving section in the second blade segment, including a span-wise bolt on the end face of the beam and at least one chord-wise bolt through the beam structure spaced from the joint line between the blade segments.

Similarly, <CIT> describes a jointed blade wherein a first blade portion and a second blade portion extend in opposite directions from a joint. Each blade portion includes a spar section forming a structural member of the blade and running lengthways, wherein the first blade portion and the second blade portion are structurally connected by a spar bridge that joins the spar sections. The spar bridge may be an extension of one of the spar sections that is received in a receiving spar section of the other blade portion. This configuration also uses a threaded bolt extending from the end face of the spar to connect and tension the spar in the receiving spar section. <CIT> discloses a method of assembling a wind turbine blade by positioning blade segments together. <CIT> discloses a wind turbine blade including segments attached together end-to-end in a predetermined arrangement.

It has been found, however, that the jointed blade configurations are susceptible to increased vibration and noise generation resulting from the joint. Relative deflections between the root-end blade segment and the tip-end blade segment result in flap-wise offsets between the shell members at the joint line. This situation is particularly present in the jointed blade designs that employ a chord-wise bolt or pin spaced (span-wise) from the joint line to transfer loads from the chord-wise bolt into the blade shells. This span-wise spacing, in combination with a difference in stiffness and orientation between the blade segment and jointed internal support structure, results in the flap-wise offsets between the shell members.

In addition to the induced flap-wise offset, torsion forces are also generated at the jointed structure that generate a twist offset between the shell members, particularly at the trailing edge of the blade.

As air flows over the shell surfaces under loaded conditions of the wind turbine, the flap-wise and/or twist-wise offsets at the joint line result in generation of turbulent vortices, which can add significantly to vibration and noise being generated at the joint line.

Therefore, an improved joint structure between the blade segments of a jointed blade that addresses the issues noted would be an advantageous advancement in the art.

These embodiments and additional non-claimed embodiments, which are examples of related techniques to help understanding the claimed invention, are further described below. The described embodiments are not to be regarded as necessarily defining the invention unless they fall within the scope of the claims.

In one non-claimed aspect, the present disclosure is directed to a method to reduce noise and vibration in a joint configuration between a first blade segment and a second blade segment of a jointed wind turbine rotor blade. Each of the first and second blade segments include a shell member having a pressure side shell component and a suction side shell component. The method includes determining an actual offset that is induced at a chord-wise joint line between the shell members of the first and second blade segments at a load condition (under defined operational conditions) on the jointed wind turbine rotor blade, wherein the actual offset is any one or combination of a flap-wise offset generated by a flap-wise force, a twist-wise offset generated by a twist-wise force, or a yawl-wise offset generated by a yawl-wise force. Based on these induced offsets, a modified configuration of the joint structure is defined at a no-load condition on the wind turbine rotor blade that compensates at least partially for one or more of the actual offset components at the load condition. The first and second blade segments are then connected or joined with the modified configuration of the joint structure, wherein at the load condition, the modified configuration of the joint structure reduces one or both of the flap-wise offset and the twist-wise offset between the shell members of the first and second blade segments.

The method is not limited to a particular joint structure between the blade segments. In a particular embodiment, however, the joint structure includes a beam structure extending span-wise from the first blade segment and a receiving section formed in the second blade segment for receipt of the beam structure, wherein the modified configuration of the joint structure includes a change in connection between the beam structure and the receiving section. For example, the first blade segment may be a tip-end blade segment, and the second blade segment is a root-end blade segment. The joint structure may include a chord-wise pin extending through the beam structure and the receiving section at a location spaced from the joint line in a span-wise direction. The modified configuration of the joint structure may include an alternate location of the chord-wise pin that compensates for one or more of the flap-wise offset, twist-wise offset, or yawl-wise offset at the load condition. The alternate location may be selected to produce one or more of a counter flap-wise offset, counter twist-wise offset, or counter yawl-wise offset at the no-load condition.

In still another embodiment of the method, the step of determining the modified configuration of the joint structure includes determining a combination of materials in the joint structure that also may contribute to reducing one or more of the flap-wise offset, twist-wise offset, or yawl-wise offset at the load condition. This combination of materials may be a stand-alone modification to the joint structure, or may be in combination with a change in location of the chord-wise pin, or other alteration of the joint structure. The change in materials may include, for example adding or removing materials from the joint structure to achieve a stiffness or torsion resistance that reduces one or more of the flap-wise offset, twist-wise offset, or yawl-wise offset at the load condition.

In particular embodiments, the load/operational condition are the variables when approaching rated output speed of a wind turbine on which the jointed wind turbine rotor blade is used, and the flap-wise offset, twist-wise offset, or yawl-wise offset at the load condition are based on an average of the respective offsets at the rated output speed over a certain range of wind speed. This determination may be an actual measurement from operational wind turbines, or may be made via computer modeling of the jointed wind turbine blade at the load condition.

The present invention also encompasses a non-claimed jointed wind turbine rotor blade with joint structure having the characteristics discussed above. In particular, such a blade includes a first blade segment and a second blade segment extending in opposite directions from a chord-wise joint line, each of the blade segments having a pressure side shell member and a suction side shell member. A joint structure is provided between the first blade segment and the second blade segment, wherein the joint structure includes a counter offset at a no-load condition on the rotor blade that compensates for one or more of a flap-wise offset, twist-wise offset, or yawl-wise offset at a load condition. With this configuration, the joint structure reduces noise and vibration generated by the jointed wind turbine rotor blade at the load condition.

In a particular blade embodiment, the joint structure includes a beam structure extending span-wise from the first blade segment, and a receiving section formed in the second blade segment for receipt of the beam structure. The first blade segment may be a tip-end blade segment, while the second blade segment is a root-end blade segment. The joint structure may include a chord-wise pin extending through the beam structure and the receiving section at a location spaced from the joint line in a span-wise direction, wherein the chord-wise pin is at a location that generates at least partly the counter offset at the no-load condition.

In a particular embodiment of the rotor blade, the joint structure includes a combination of materials that may also aid in reducing one or more of the flap-wise offset, twist-wise offset, or yawl-wise offset at the load condition. This combination of materials may be a stand-alone modification to the joint structure, or may be in combination with a change in location of the chord-wise pin. The change is materials may include, for example adding or removing materials from the joint structure to achieve a stiffness or torsion resistance that reduces one or both of the flap-wise offset and the twist-wise offset at the load condition.

The present invention also encompasses a jointed wind turbine rotor blade according to independent claim <NUM> with a sealing tape configuration that reduces blade vibration and noise at operating conditions of the wind turbine. The jointed wind turbine rotor blade includes a first blade segment and a second blade segment extending in opposite directions from a chord-wise joint line, wherein each of the blade segments has a pressure side shell member and a suction side shell member. A sealing tape is applied over the pressure side shell member and the suction side shell member along the chord-wise joint line. The sealing tape has side edges that are non-perpendicular to a leading edge of the wind turbine blade and that are aligned parallel with airflow over the pressure side shell member and the suction side shell member at the chord-wise joint line at a defined load/operational condition on the jointed wind turbine blade. The tape edges and cross-sectional shape of the tape define a raised profile relative to the surface of the shell members. By aligning the edges of the tape to be parallel to airflow over the blade, the noise and blade vibrations that would otherwise be induced by the presence of the tape are minimized.

The sealing tape may have a constant cross-sectional profile along an entire longitudinal length thereof, wherein such profile may include a relatively thick center section that tapers to the opposite side edges of the tape. In a particular embodiment, the sealing tape may include a deformable medial spacer designed to protrude or fit between the first and second blade segments along the chord-wise joint line. This spacer may serve to dampen any one or combination of the flap-wise, twist-wise, or yawl-wise forces acting on the replacement blade tip segment, as discussed above.

In certain embodiments, the chord-wise joint line is also oriented parallel with the airflow over the pressure side shell member and the suction side shell member at the load condition. However, this embodiment may increase the complexity, time, and expense of the joint structure between the blade segments. Thus, in another embodiment, the length of the chord-wise joint line is minimized and is oriented generally perpendicular to a leading edge of the jointed wind turbine blade. With this arrangement, the side edges of the sealing tape are non-parallel to the chord-wise joint line, but are maintained parallel to airflow over the blade surfaces. With this embodiment, the sealing tape may include the deformable spacer, wherein the spacer is defined on an underside of the sealing tape in a non-parallel orientation relative to the side edges of the sealing tape.

With the above embodiment, the sealing tape may be continuous and have a length so as to wrap around the pressure and suction side shell members, wherein opposite ends of the sealing tape meet at a trailing edge of the jointed wind turbine blade. The spacer in this embodiment extends at opposite and equal angles from a mid-point of the sealing tape.

In another embodiment, the sealing tape includes a first tape segment applied to the pressure side shell member and a second tape segment applied to the suction side shell member, wherein the first and second tape segments are joined at a first seam at a leading edge of the jointed wind turbine blade and a second seam at a trailing edge of the jointed wind turbine blade.

The sealing tape may be made of any suitable pliable material that can conform to the shape of the blade shell members, such as a natural or synthetic web material, a vinyl or plastic material, a composite material, and the like. The sealing tape can be applied to the blade shell members with any suitable adhesive. In a particular embodiment, the sealing tape includes a pre-applied adhesive on an underside thereof for attachment to the pressure and suction side shell members.

These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description and appended claims.

Generally, the present subject matter is directed to jointed wind turbine rotor blades having a modified joint structure configuration that serves to compensate for or counter one or both of flap-wise and twist-wise offsets between the blade segments at a load condition on the rotor blade. With the present unique method and rotor blade configuration, noise and vibration generated at the joint line between the blade segments is reduced.

Referring now to the drawings, <FIG> is a side view of an exemplary wind turbine <NUM> that may use jointed wind turbine rotor blades in accordance with an embodiment of the present invention. In this embodiment, the wind turbine <NUM> is a horizontal-axis wind turbine. In the present embodiment, the wind turbine <NUM> includes a tower <NUM> that extends from a support surface <NUM>, a nacelle <NUM> mounted on the tower <NUM>, a generator <NUM> positioned within the nacelle <NUM>, a gearbox <NUM> coupled to the generator <NUM>, and a rotor <NUM> that is rotationally coupled to the gearbox <NUM> with a rotor shaft <NUM>. The rotor <NUM> includes a rotatable hub <NUM> and at least one rotor blade <NUM> coupled to and extending outward from the rotatable hub <NUM>. As shown, the rotor blade <NUM> includes a blade tip <NUM> to a blade root <NUM>.

Referring to <FIG>, a jointed rotor blade <NUM> is depicted having a first blade segment <NUM> and a second blade segment <NUM> in accordance with aspects of the present technology. The first blade segment <NUM> and the second blade segment <NUM> extend in opposite directions from a chord-wise joint line <NUM>. Each of the blade segments <NUM>, <NUM> includes a pressure side shell member <NUM> and a suction side shell member <NUM>. The first blade segment <NUM> and the second blade segment <NUM> are connected by an internal support structure <NUM> extending into both blade segments <NUM>, <NUM> to facilitate joining of the blade segments <NUM>, <NUM>. The arrow <NUM> shows that the segmented rotor blade <NUM> in the illustrated example includes two blade segments <NUM>, <NUM> and that these blade segments <NUM>, <NUM> are joined by inserting the internal support structure <NUM> into the second blade segment <NUM>.

In the depicted embodiment, the first blade segment includes a beam structure <NUM> that forms a portion of the internal support structure <NUM> and extends lengthways (e.g., span-wise) for structurally connecting with the internal support structure <NUM> in the second blade segment <NUM>. The beam structure <NUM> may be integrally formed with the first blade segment <NUM> as an extension protruding from a spar section <NUM>, thereby forming an extended spar section. The beam structure <NUM> includes at least one interconnecting web <NUM> (e.g., a shear web) connected with a suction side spar cap <NUM> and a pressure side spar cap <NUM>. In the illustrated embodiments, the beam structure <NUM> is formed as a box-type structure having opposite interconnecting webs <NUM>.

The first blade segment <NUM> may include one or more first bolt joints (also referred to as "pins") towards a first end <NUM> of the beam structure <NUM>. For example, a bolt <NUM> may be located on the end <NUM> of the beam structure <NUM> and oriented in a span-wise direction. The first blade segment <NUM> may also include a bolt joint slot <NUM> located on the beam structure <NUM> proximate to the chord-wise joint <NUM> and oriented in a chord-wise direction. There may be a bushing within the bolt joint slot <NUM> arranged in a tight interference fit with a bolt tube or pin <NUM> used to connect the second blade segment <NUM> to first blade segment <NUM>. It should be appreciated that any combination of bolt tubes <NUM>, <NUM> and bolt slots <NUM> may be configured between the beam structure <NUM> and a receiving section <NUM> (<FIG>) for the purpose of interconnecting the first <NUM> and second <NUM> blade segments.

In <FIG>, the second blade segment <NUM>, the internal support structure <NUM> includes a receiving section <NUM> extending lengthways (span-wise) within the second blade segment <NUM> for receiving the beam structure <NUM> of the first blade segment <NUM>. The receiving section <NUM> includes multiple spar structure components <NUM> that extend lengthways for connecting with the beam structure <NUM> of the first blade segment <NUM> along a length of the receiving section <NUM>. Although not depicted in <FIG>, it is readily understood that the receiving section <NUM> includes any combination of bolt slots <NUM> or bolts <NUM>, <NUM> for interconnecting with corresponding bolts or slots of the beam structure <NUM>. For example, a bolt slot is configured in a distal end (away from the chord-wise joint <NUM>) of the receiving section <NUM> for receipt of the bolt <NUM> provided on the end <NUM> of the beam structure <NUM>.

<FIG> depicts the concepts of flap-wise <NUM>, twist-wise <NUM>, and yawl-wise <NUM> forces acting on the jointed wind turbine blade, wherein such forces can respectively generate a flap-wise offset <NUM> (<FIG>), a twist-wise offset <NUM> (<FIG>), and a yawl-wise offset <NUM> (<FIG>) between the shell components of the first and second blade segments <NUM>, <NUM> at the chord-wise joint <NUM>. These offset components <NUM>, <NUM>, and <NUM> can combine to induce an actual offset <NUM> between the shell components. The flap-wise forces <NUM> tend to act uniformly across the chord aspect of the first blade segment <NUM> causing the first blade segment <NUM> to essentially "bend" towards the second blade segment <NUM> and displace the shell members <NUM> in a vertical direction <NUM> along the chord-wise joint <NUM>. The twist-wise forces <NUM> tend to generate a twisting of the first blade segment <NUM> relative to the second blade segment <NUM> along a span-wise axis of the blade resulting in a twist-wise offset <NUM> of the shell members <NUM> along the chord-wise joint <NUM>. The yawl-wise forces <NUM> tend to generate a side-ways movement of the first blade segment <NUM> relative to the second blade segment <NUM> transverse to the span-wise axis of the blade resulting in a yawl-wise offset <NUM> of the shell members <NUM> along the chord-wise joint <NUM>. As explained above, these induced offsets <NUM>, <NUM>, <NUM> can generate excessive vibrations and noise in the blade <NUM> at operational load on the wind turbine (load on the turbine blades <NUM> when the wind turbine <NUM> is operating in the rated power output range of the power curve).

<FIG> depicts the actual offset <NUM> as a combination of the flap-wise offset <NUM> and the yawl-offset <NUM>. <FIG> depicts the actual offset <NUM> as a combination of the flap-wise offset <NUM>, the twist-wise offset <NUM>, and the yawl-wise offset <NUM>. It should be appreciated that the actual offset <NUM> may be induced from any one or combination of the offset components <NUM>, <NUM>, and <NUM>.

In addition, referring to <FIG>, the blades <NUM> may be designed with a no-load moderate sweep inboard (closer to blade root) relative to blade pitch axis P, while the outboard section (closer to the blade tip) may be swept aft up to <NUM> degrees (angle θ in <FIG>) relative to pitch axis P.

In <FIG>, determination and compensation for a flap-wise offset <NUM> induced in the blade <NUM> under load is depicted in accordance with aspects of the present disclosure. Similarly, in <FIG>, determination and compensation for a twist-wise offset <NUM> induced in the blade <NUM> under load is depicted. It should be appreciated that similar methods can be employed for determination and compensation for the yawl-wise offset.

Referring to <FIG> and <FIG>, the jointed blade <NUM> is depicted at the chord-wise joint <NUM> in an initial unloaded condition wherein an initial negligible flap-wise or twist-wise offset is induced in the blade at the joint <NUM>. <FIG> depicts the same jointed blade <NUM> at an initial loaded condition, for example under load at rated power of the wind turbine, wherein a flap-wise offset <NUM> is depicted between the shell members of the first blade segment <NUM> and the second blade segment <NUM> at the chord-wise joint <NUM>. Similarly, <FIG>, depicts the jointed blade <NUM> in an initial loaded condition, for example under load when approaching or at rated power of the wind turbine, wherein a twist-wise offset <NUM> is depicted between the shell members of the first blade segment <NUM> and the second blade segment <NUM> at the chord-wise joint <NUM>. The present method includes determining the magnitude of one or both of the flap-wise offset <NUM> and twist-wise offset <NUM>. This determination may be done by measurement of the actual offset at the chord-wise joint <NUM> with sensors, camera, and so forth, when the blade <NUM> (or similar blade) is under load at defined operational conditions. Alternatively, the actual offset may be determined via a suitable modeling program. As mentioned, it is appreciated that the actual offset <NUM> at the chord-wise joint <NUM> may be a combination of the flap-wise offset <NUM>, the twist-wise offset <NUM>, and the yawl-wise offset <NUM>. Also, any one of these offsets may be negligible, wherein the actual offset is due primarily to one or a combination of the other offsets under load on the blade <NUM>.

Referring to <FIG>, based on the actual offset induced at the joint <NUM> with the blade <NUM> under load, a modified configuration of the joint structure <NUM> is defined at a no-load condition on the blade <NUM> that will compensate for the induced offset. This modified configuration may only compensate for one of the flap-wise offset <NUM> or the twist-wise offset <NUM>, but preferably compensates for both types of offsets <NUM>, <NUM>.

It should be appreciated that the present methods encompass the scenario wherein the actual offset <NUM> is determined empirically or via computer modeling for a particular type of blade at a defined location and under defined operational conditions, and this offset <NUM> is then used to define the modified configuration for a subsequent number of blades <NUM>. It is not necessary to determine the actual offset and modified configuration on an individual basis for every blade <NUM>.

As mentioned, the modified configuration of the joint structure <NUM> may include determining a combination of materials in the joint structure <NUM> that reduces one or both of the flap-wise offset <NUM> and the twist-wise offset <NUM> at the load condition. This combination of materials may be a stand-alone modification to the joint structure, or may be in combination with a change in location of the components of the joint structure <NUM>, as described below. The change in materials may include, for example adding or removing materials from the joint structure <NUM> to achieve a stiffness or torsion resistance that reduces one or both of the flap-wise offset <NUM> and the twist-wise offset72 at the load condition.

<FIG> depicts an embodiment wherein the joint structure <NUM> is structurally modified in an unloaded state of the blade <NUM> to compensate for the induced flap-wise offset <NUM> (<FIG>) at a load condition. In this embodiment, the joint structure <NUM> includes the beam structure <NUM> extending span-wise from the first blade segment <NUM> (tip-end segment) and a receiving section <NUM> formed in the second blade segment <NUM> (root-end segment) for receipt of the beam structure <NUM>. The modified configuration of the joint structure <NUM> includes a change in connection between the beam structure <NUM> and the receiving section <NUM>. The joint structure <NUM> includes a chord-wise pin <NUM> extending through the beam structure <NUM> and the receiving section <NUM> at a location spaced from the joint line <NUM> in a span-wise direction. An alternate location of the chord-wise pin <NUM> is determined that compensates for the flap-wise offset <NUM> at the load condition, wherein the alternate location is selected to produce a counter flap-wise offset at the no-load condition on the blade <NUM>. For example, as exaggerated in <FIG> for illustrative purposes, the chord-wise pin <NUM> may be lowered or raised towards the pressure or suction side of the blade <NUM> relative to the initial position depicted in <FIG> to produce the counter flap-wise offset.

Similarly, <FIG> depicts an embodiment wherein the joint structure <NUM> is structurally modified in an unloaded state of the blade <NUM> to compensate for the induced twist-wise offset <NUM> (<FIG>) at a load condition. The modified configuration of the joint structure <NUM> includes a change in connection between the beam structure <NUM> and the receiving section <NUM>. The joint structure <NUM> includes the chord-wise pin <NUM> extending through the beam structure <NUM> and the receiving section <NUM> at a location spaced from the joint line <NUM> in a span-wise direction. An alternate location of the chord-wise pin <NUM> is determined that compensates for the twist-wise offset <NUM> at the load condition, wherein the alternate location is selected to produce a counter twist-wise offset at the no-load condition on the blade <NUM>. For example, as exaggerated in <FIG> for illustrative purposes, the chord-wise pin <NUM> may be rotated from the initial orientation depicted in <FIG> to the modified position in <FIG> to produce the counter twist-wise offset.

Once the modifications to the joint structure <NUM> are determined, the jointed blade <NUM> is assembled in accordance with such modifications. <FIG> depicts the modified assembled jointed blade <NUM> in an unloaded state, and <FIG> depicts the blade <NUM> under load wherein the flap-wise offset <NUM> present in <FIG> has been compensated for by the modifications depicted in <FIG>. Likewise, <FIG> depicts the modified assembled jointed blade <NUM> in an unloaded state, and <FIG> depicts the blade <NUM> under load wherein the twist-wise offset <NUM> present in <FIG> has been compensated for by the modifications depicted in <FIG>.

The present invention also encompasses a jointed wind turbine rotor blade <NUM> with joint structure <NUM> having the characteristics discussed above.

Referring to <FIG>, the present invention also encompasses a jointed wind turbine rotor blade <NUM> with a sealing tape <NUM> configuration that reduces blade vibration and noise at operating conditions of the wind turbine. The jointed wind turbine rotor blade <NUM> includes the first blade segment <NUM> and second blade segment <NUM> extending in opposite directions from the chord-wise joint line <NUM>, wherein each of the blade segments <NUM>, <NUM> has a pressure side shell member <NUM> and suction side shell member <NUM>. It should be appreciated that the sealing tape <NUM> configuration may be incorporated with the jointed wind turbine blade <NUM> having the characteristics discussed above with respect to the embodiments of <FIG> and, in that regard, the discussion of <FIG> is incorporated herein with respect to <FIG>. Alternatively, the sealing tape <NUM> configuration may be used as a stand-alone component on a jointed wind turbine blade that does not include the modified joint structure of <FIG>.

The sealing tape <NUM> is applied over the pressure side shell member <NUM> and the suction side shell member <NUM> so as to bridge across the chord-wise joint line <NUM>. The sealing tape <NUM> has side edges <NUM> that protrude to at least some extend from the shell members <NUM>, <NUM>. The sealing tape is oriented on the shell members <NUM>, <NUM> so that the side edges <NUM> are aligned parallel with airflow <NUM> over the shell members <NUM>, <NUM> at the chord-wise joint line <NUM> at a defined load condition on the jointed wind turbine blade <NUM>, such as the load condition at rated output speed of a wind turbine on which the jointed wind turbine rotor blade <NUM> is used. The tape edges <NUM> and cross-sectional shape of the tape <NUM> define a raised profile relative to the surface of the shell members <NUM>, <NUM>. By aligning the edges <NUM> of the tape <NUM> to be parallel to airflow <NUM> over the blade, the noise and blade vibrations that would otherwise be induced by the presence of the tape <NUM> are minimized.

The sealing tape <NUM> may have a constant cross-sectional profile <NUM> along an entire longitudinal length thereof, as depicted in <FIG>, wherein such profile may include a relatively thick center section <NUM> that tapers to the opposite side edges <NUM> of the tape. In a particular embodiment, the sealing tape <NUM> may include a deformable medial spacer <NUM> (<FIG>) or wedge <NUM> (<FIG>) formed or attached to an underside <NUM> of the tape <NUM> and designed to protrude or fit between the first 31and second <NUM> blade segments along the chord-wise joint line <NUM>, as depicted by the dashed lines in <FIG>. This spacer <NUM> or wedge <NUM> is preferably formed of the same material as the tape <NUM> or may be a separate component that is fixed to the underside <NUM> of the tape <NUM>. The spacer <NUM> or wedge <NUM> is compressible when forces acting on the blade tip segment <NUM> induce the offsets discussed above between the blade tip segment <NUM> and segment <NUM> and thus serve to dampen any one or combination of the flap-wise, twist-wise, or yawl-wise forces acting on the replacement blade tip segment <NUM>.

It should be appreciated that "load condition" as used herein may also refer to defined operational conditions and environment determined or expected for the wind turbine that could affect flow over the blade and, thus, may entail more than consideration of load at a point on the wind turbine power curve.

Referring to <FIG>, in certain embodiments, the chord-wise joint line <NUM> is also oriented parallel to the airflow <NUM> over the shell members <NUM>, <NUM> at the load condition. However, this embodiment may increase the complexity, time, and expense of forming the joint structure between the blade segments <NUM>, <NUM>. Thus, in another embodiment depicted in <FIG>, the length of the chord-wise joint line <NUM> is minimized and is oriented generally perpendicular to the leading edge <NUM> of the jointed wind turbine blade <NUM>. With this arrangement, the side edges <NUM> of the sealing tape <NUM> are non-parallel to the chord-wise joint line <NUM>, but are maintained parallel to airflow <NUM> over the blade surfaces, as seen in <FIG>. With this embodiment, the sealing tape <NUM> may include the deformable spacer <NUM> or wedge <NUM>, wherein the spacer <NUM> or wedge <NUM> are defined on the underside <NUM> of the sealing tape <NUM> in a non-parallel orientation relative to the side edges <NUM> of the sealing tape <NUM>.

Referring to <FIG>, with the above embodiment, the sealing tape <NUM> may be continuous and have a length so as to wrap around the pressure and suction side shell members <NUM>, <NUM>, wherein opposite ends of the sealing tape <NUM> meet at seam <NUM> (<FIG>) at the trailing edge <NUM> of the jointed wind turbine blade <NUM>. The spacer <NUM> or wedge <NUM> in this embodiment extends at opposite and equal angles from a mid-point <NUM> of the sealing tape <NUM> that corresponds to the relative location of the leading edge <NUM> when the tape <NUM> is applied on the blade <NUM>.

Referring to <FIG> and <FIG>, in another embodiment, the sealing tape <NUM> includes a first tape segment <NUM> applied to the pressure side shell member <NUM> and a second tape segment <NUM> applied to the suction side shell member <NUM>, wherein the first <NUM> and second <NUM> tape segments are joined at a first seam <NUM> at the leading edge <NUM> of the jointed wind turbine blade28 and a second seam <NUM> at the trailing edge <NUM> of the jointed wind turbine blade <NUM>.

Claim 1:
A jointed wind turbine rotor blade (<NUM>), comprising:
a first blade segment (<NUM>) and a second blade segment (<NUM>) extending in opposite directions from a chord-wise joint line (<NUM>), each of the blade segments having a pressure side shell member (<NUM>) and a suction side shell member (<NUM>);
a sealing tape (<NUM>) applied over the pressure side shell member (<NUM>) and the suction side shell member (<NUM>) along the chord-wise joint line (<NUM>); characterized in that
the sealing tape (<NUM>) comprises side edges (<NUM>) that are non-perpendicular to a leading edge (<NUM>) of the wind turbine blade and that are aligned parallel with airflow (<NUM>) over the pressure side shell member (<NUM>) and the suction side shell member (<NUM>) at the chord-wise joint line (<NUM>) at a defined load and operational condition on the jointed wind turbine blade (<NUM>) so that blade vibration and noise are reduced.