BUILDING STRUCTURE WITH MEANS TO REDUCE INDUCED VIBRATIONS

Abstract

An arrangement to reduce vortex induced vibrations in a building structure is provided. A building structure is disclosed, including an outer surface, whereby a vortex generator is connected to the outer surface of the building structure. The vortex generator is prepared and arranged in a way to generate vortices in an airstream passing by the outer surface.

Claims

1. A building structure, comprising an outer surface, wherein a vortex generator is connected to the outer surface of the building structure, the vortex generator configured to generate vortices in an airstream passing by the outer surface.

2. The building structure according to claim 1, wherein the vortex generator comprises a plurality of fins, that are arranged in a row.

3. The building structure according to claim 2, wherein the fins comprise a tip with a maximum elevation vertical to the outer surface, and a rim adjacent to the tip that comprises a decreasing elevation vertical to the outer surface.

4. The building structure according to claim 2, wherein the fins are oriented in an angle of up to 60 from a horizontal direction, wherein the horizontal direction is determined when the building structure is in an installed state.

5. The building structure according to claim 4, wherein at least two neighboring fins of the row, are angled in respect to the horizontal orientation in an alternating way, so that the at least two neighboring fins converge at one of their ends.

6. The building structure according to claim 2, wherein the row of the fins is arranged in a substantially vertical direction along a length of the building structure, wherein the substantially vertical direction of the building structure is determined when the building structure is oriented as installed.

7. The building structure according to claim 2, wherein at least two rows of fins are arranged along the outer surface of the building structure.

8. The building structure according to claim 7, wherein the at least two rows of fins are arranged at a different position along a circumference of the outer surface of the building structure.

9. The building structure according to claim 8, wherein the at least two rows of fins are arranged at positions which are spaced substantially 30, 60, 90, or 120 measured along the circumference of the outer surface of the building structure.

10. The building structure according to claim 2, wherein the row of fins is connected to a common base and the common base is connected with the outer surface of the building structure.

11. The building structure according to claim 1, wherein a section of the upper part of the building structure is equipped with a plurality of vortex generators, wherein at least 10% of the length of the building structure is equipped with the vortex generators.

12. The building structure according to claim 11, wherein at least 30% of the length of the building structure is equipped with the vortex generators.

13. The building structure according to claim 1, wherein the outer surface of the building structure comprises a flap that is angled substantially vertical to the outer surface and extends along at least a part of the length of the building structure.

14. The building structure according to claim 1, wherein the building structure is a chimney or a tower.

15. The building structure according to claim 14, wherein the tower is a tower of a wind turbine.

Description

BRIEF DESCRIPTION

[0096] Some of the embodiments will be described in detail, with references to the following Figures, wherein like designations denote like members, wherein:

[0097] FIG. 1 shows vortex generators at a building structure;

[0098] FIG. 2 shows a detailed view of the vortex generators of FIG. 1;

[0099] FIG. 3 A shows a flap at the building structure

[0100] FIG. 3 B shows a detailed view of a flap; and

[0101] FIG. 4 shows the effect of a vortex generator and a flap.

DETAILED DESCRIPTION

[0102] FIG. 1 shows vortex generators at a building structure.

[0103] FIG. 1 shows a building structure 1 with an outer surface 2. Vortex generators 3 are attached to the outer surface 2 of the building structure 1.

[0104] The vortex generators 3 are arranged in rows of fins 9, 10 that are oriented mainly along the longitudinal direction of the building structure 1.

[0105] In FIG. 1 the building structure 1 is a tubular chimney or tower.

[0106] When the section of the tubular chimney or tower displayed in FIG. 1 is in an installed and upright direction, the rows of fins 9, 10 are oriented along the outer surface 2 of the building structure 1 in a mainly vertical direction.

[0107] The rows of fins 9, 10 are spaced apart from each other along the outer surface 2 of the building structure 1 by a certain angle measured along the circumference of the outer surface 2 of the building structure 1. The angle between two rows of fins 9, 10 is 30 degrees, for example.

[0108] Several rows of fins are stacked vertically above each other, and show a certain offset in respect to each other in the position along the circumference of the rows on the outer surface of the building structure.

[0109] Wind blowing along the outer surface 2 of the building structure 1 interacts with the fins of the vortex generators 3. The energy of the airflow close to the outer surface 2 of the building structure 1 is leveled out by the interaction of the air with the fins of the vortex generators 3.

[0110] Thus, the airflow stays a longer distance close to the surface of the building structure before it leaves the surface in the wake of the building structure, and creates a vortex street.

[0111] Thus, the creation of vortices in the vortex street is reduced.

[0112] FIG. 2 shows a detailed view of the vortex generators 3.

[0113] FIG. 2 shows a building structure 1 with an outer surface 2. Vortex generators 3 are connected to the outer surface 2 of the building structure 1.

[0114] The vortex generators 3 comprise a common base for fins such as fins 5 and 6.

[0115] The rows of fins 9 and 10 are oriented mainly vertical along the building structure whereby the vertical direction is determined when the building structure 1 is in an installed position.

[0116] The fins 5, 6 of the vortex generator 3 show a tip 7 and a rim 8 that is in communication with the tip 7. The tip 7 of the fin 5, 6 of the vortex generator 3 is the point of the fin with the highest elevation of the fin in respect to the outer surface 2 of the building structure 1. The height of the fin decreases along the rim 8 of the fin 5, 6.

[0117] The wind blowing along the outer surface 2 of the building structure 1 interacts with the fins 5, 6. As the direction of the wind varies in respect to the building structure 1, the fins of the vortex generator 3 show a different orientation of the tip 7 of the fin 5, 6 in respect to the wind direction.

[0118] The fins 5, 6 are angled in respect to a horizontal direction measured along the outer surface 2 of the building structure 1, whereby a horizontal direction is determined when the building structure 1 is in an installed, and thus upright position.

[0119] The fins 5, 6 are angled in respect to a horizontal position in an angle of up to 60 degrees. Seen from the tip 7 of the fin 5, 6, the direction of the fin along the rim 8 can deviate with respect to the horizontal position in a direction of minor 60 degrees or in a direction of plus 60 degrees in respect to the horizontal direction.

[0120] Neighboring fins 5, 6 are oriented in an alternating way. Thus, neighboring fins 5, 6 shown an orientation in respect to each other that is V-shaped.

[0121] Thus, one end of the fins is closer to the neighboring fin than the other end. Seen in a row of fins, such as rows of fins 9, 10, this leads to a zigzag shaped arrangement of the fins.

[0122] Different rows 9, 10 of fins 5, 6 are distributed along the circumference of the outer surface 2 of the building structure 1.

[0123] FIG. 3a shows a flap at a building structure.

[0124] FIG. 3a shows a flap 11 that is connected to the outer surface 2 of the building structure 1 in addition to the vortex generators. The flap is attached to the building structure 1 at a certain angular position 14 and comprises a height 12.

[0125] FIG. 3b shows a detailed view of a flap.

[0126] FIG. 3b shows the flap 11 with a certain height 12, and a base 13 to attach the flap to the outer surface of the building structure 1.

[0127] The height of the flap is arranged vertical in respect to the outer surfaces of the building structure 1, whereby the flap has a longitudinal direction that is oriented in parallel to the longitudinal direction of the building structure 1.

[0128] FIG. 4 shows the effect of a vortex generator and a flap.

[0129] FIG. 4 shows the building structure 1 in a horizontal crosscut. The building structure shows a circular shape, and can be a chimney or a tower, for example.

[0130] The building structure 1 comprises an outer surface 2. A vortex generator 3 is attached to the outer surface 2 at a first position along the circumference of the building structure. A flap 11 is attached to the outer surface 2 at a second position.

[0131] In FIG. 4 the flap 11 and the vortex generator 3 are spaced mainly 180 degrees apart from each other along the circumference.

[0132] A wind 15 blows towards the building structure 1. The air stream gets divided at the front side of the building structure 1, and flows in a mainly laminar flow along the outer surface 2 of the building structure in two directions. The air flow at one side meets the vortex generator 3, the air flow at the other side of the building structure 1 meets the flap 11.

[0133] The vortex generator influences the airflow in a way that the airstream stays close to the outer surface 2 of the building structure 1 for a longer distance along the circumference as a laminar airflow 16.

[0134] The flap 11 interacts with the airflow in a way to force the creation of vortices 17 that separate the laminar airflow from the outer surface 2 of the building structure 1. Behind the flap 11 the vortices 17 are created earlier along the circumference as they would be created without the flap 11. In addition, a different vortex pattern is created.

[0135] The combination of a vortex generator 3 and a flap 11 leads to smaller vortices 17, that are offset from the middle of the wake zone of the building structure. The vortex street created is offset to the side of the building structure 1 that comprises the flap 11.

[0136] Thus, the vortex street has less influence on the building structure 1. The building structure takes in less loads from the vortices 17 in the wake of the building structure 1. Thus, the building structure can be built less rigid and with less material. Thus material, weight, and costs are saved.

[0137] The illustration in the drawings is in schematic form. It is noted that in different figures, similar or identical elements are provided with the same reference signs.

[0138] Although the invention has been illustrated and described in greater detail with reference to the preferred exemplary embodiment, the invention is not limited to the examples disclosed, and further variations can be inferred by a person skilled in the art, without departing from the scope of protection of the invention.

[0139] 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.