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Damping of oscillations of the first bending mode of a wind turbine is performed means of one or more containers partly filled with a liquid for damping oscillations of the first natural bending frequency of the wind turbine. The damping means comprises a plurality of box shaped containers having a

Damping of oscillations of the first bending mode of a wind turbine is performed means of one or more containers partly filled with a liquid for damping oscillations of the first natural bending frequency of the wind turbine. The damping means comprises a plurality of box shaped containers having a square cross section and being partly filled with liquid so as to provide a unidirectional damping with a logarithmic decrement of oscillations of the first natural bending frequency of the wind turbine of at least 4-8%. For off-shore wind turbines, the combined excitation of the wind and sea waves requires more damping, the damping is preferably equivalent to a logarithmic decrement of 10-15%. Furthermore, the invention relates to damping of oscillation of the second bending mode of a wind turbine and to the combined damping of oscillations of the first as well as the second bending mode of the wind turbine.

대표청구항 ▼

Damping of oscillations of the first bending mode of a wind turbine is performed means of one or more containers partly filled with a liquid for damping oscillations of the first natural bending frequency of the wind turbine. The damping means comprises a plurality of box shaped containers having a

Damping of oscillations of the first bending mode of a wind turbine is performed means of one or more containers partly filled with a liquid for damping oscillations of the first natural bending frequency of the wind turbine. The damping means comprises a plurality of box shaped containers having a square cross section and being partly filled with liquid so as to provide a unidirectional damping with a logarithmic decrement of oscillations of the first natural bending frequency of the wind turbine of at least 4-8%. For off-shore wind turbines, the combined excitation of the wind and sea waves requires more damping, the damping is preferably equivalent to a logarithmic decrement of 10-15%. Furthermore, the invention relates to damping of oscillation of the second bending mode of a wind turbine and to the combined damping of oscillations of the first as well as the second bending mode of the wind turbine. spacings are configured to control a first portion of said coolant in said leading pressure edge section and a second portion of said coolant in said trailing pressure edge section, respectively. 10. The apparatus of claim 7 wherein said leading pressure edge section is further configured with at least one airfoil leading edge cooling ejection; wherein said trailing pressure edge section is further configured with at least one airfoil trailing edge cooling ejection. 11. The apparatus of claim 1, further comprising: a suction side double wall; an external suction side plate comprising a plurality of external suction ribs; an internal suction side plate comprising a plurality of internal suction ribs; a plurality of suction flow redirection areas; and said external suction side plate disposed over said internal suction side plate so as to form said suction side double wall; wherein said external suction ribs are disposed at said first angle with respect to said blade span reference line and said internal suction ribs are disposed at said second angle with respect to said blade span reference line so as to form said suction flow redirection areas; wherein said suction side double wall is configured so as to pass a portion of said coolant through said pressure side double wall. 12. The apparatus of claim 11, wherein said first angle has a range from about 25 degrees to about 55 degrees, wherein said second angle has a range from about -25 to about -55 degrees. 13. The apparatus of claim 11, wherein said first angle has a range from about 40 degrees to about 45 degrees, wherein said second angle said has a range from about -40 to about -45 degrees. 14. The apparatus of claim 11, wherein said first angle has a range from about -25 degrees to about -55 degrees, wherein said second angle has a range from about 25 to about 55 degrees. 15. The apparatus of claim 11, wherein said first angle has a range from about -40 degrees to about -45 degrees, wherein said second angle has a range from about 40 to about 45 degrees. 16. The apparatus of claim 11 further comprising a plurality of concavities (310); wherein at least a portion of at least one of said external suction ribs, said internal suction ribs, said external suction side plate, said internal suction side plate, said external pressure ribs, said internal pressure ribs, said external pressure side plate, and said internal pressure side plate that is disposed to contact said coolant is configured with said plurality of concavities thereon. 17. The apparatus of claim 11, wherein said pressure side double wall and said suction side double wall are disposed from about a blade root to about a blade cover. 18. The apparatus of claim 11 further comprising: a leading pressure edge cover; a trailing pressure edge cover; a leading suction edge cover; a trailing suction edge cover; wherein said leading pressure edge cover is disposed to said external pressure side plate and said internal pressure side plate; wherein said trailing pressure edge cover is disposed to said external pressure side plate and said internal pressure side plate; wherein said leading suction edge cover is disposed to said external suction side plate and said internal suction side plate; wherein said trailing suction edge cover is disposed to said external suction side plate and said internal suction side plate; wherein said external pressure side plate, said internal pressure side plate, said external suction side plate, said internal suction side plate, said leading pressure edge cover, said trailing pressure edge cover, said trailing suction edge cover, and said leading suction edge cover are disposed in an investment casting. 19. The apparatus of claim 18 further comprising: a suction side dividing rib disposed between said external suction side plate and said internal suction side plate; wherein said suction side dividing rib divides said suction side double wall into a leading suction edge section and a trailing suction edge section; wherein said external pressure side plate, said internal pressure side plate, said external suction side plate, said internal suction side plate, said leading pressure edge cover, said trailing pressure edge cover, said trailing suction edge cover, said leading suction edge cover and said suction side dividing rib are disposed in an investment casting. 20. The apparatus of claim 19 further comprising: a pressure side dividing rib disposed between said external pressure side plate and said internal pressure side plate; wherein said pressure side dividing rib divides said pressure side double wall into a leading pressure edge section and a trailing pressure edge section; wherein said external pressure side plate, said internal pressure side plate, said external suction side plate, said internal suction side plate, said leading pressure edge cover, said trailing pressure edge cover, said trailing suction edge cover, said leading suction edge cover, said pressure side dividing rib, and said suction side dividing rib are disposed in an investment casting. 21. The apparatus of claim 20, wherein said leading pressure edge section has a first rib spacing and said trailing pressure edge section has a second rib spacing; wherein said first rib spacing and said second rib spacings are configured to control a first portion of said coolant in said leading pressure edge section and a second portion of said coolant in said trailing pressure edge section, respectively; wherein said leading suction edge section has a third rib spacing and said trailing suction edge section has a fourth rib spacing; wherein said third rib spacing and said fourth rib spacings are configured to control a third portion of said coolant in said leading suction edge section and a fourth portion of said coolant in said trailing suction edge section, respectively. 22. The apparatus of claim 21 wherein said leading pressure edge section is further configured with at least one airfoil leading edge cooling ejection; wherein said trailing pressure edge section is further configured with at least one airfoil trailing edge cooling ejection; wherein said leading suction edge section is further configured with said at least one airfoil leading edge cooling ejection; wherein said trailing suction edge section is further configured with said at least one airfoil trailing edge cooling ejection. 23. A turbine blade comprising: a external pressure side plate comprising a plurality of external pressure ribs; an internal pressure side plate comprising a plurality of internal pressure ribs; an external suction side plate comprising a plurality of external suction ribs; an internal suction side plate comprising a plurality of internal suction ribs; a plurality of pressure flow redirection areas; a plurality of suction flow redirection areas; said external pressure side plate disposed over said internal pressure side plate so as to form a pressure side double wall; and said external suction side plate disposed over said internal suction side plate so as to form a suction side double wall; wherein said external pressure ribs are disposed at a first angle with respect to a blade span reference line and said internal pressure ribs are disposed at a second angle with respect to said blade span reference line so as to form said pressure flow redirection areas; wherein said external suction ribs are disposed at said first angle with respect to said blade span reference line and said internal suction ribs are disposed at said second angle with respect to said blade span reference line so as to form said suction flow redirection areas; wherein said pressure side double wall is configured so as to pass a portion of a coolant through said pressure side double wall; wherein said suction side double wall is configured so as to pass said another portion of said coolant through said suction side double wa