Suppression element for vortex vibrations

A suppression element for vortex vibrations, wherein:

• the suppression element has a longitudinal direction, as well as a circumferential direction around a reference axis which is parallel to the longitudinal direction, and wherein the suppression element has an inner side and an opposite outer side, wherein the inner side has a concave shape in the circumferential direction and the outer side has a convex shape in the circumferential direction, and wherein the suppression element on both ends in the longitudinal direction has a first end edge and an opposite second end edge, and wherein the suppression element on both ends in the circumferential direction has a first longitudinal edge and an opposite second longitudinal edge;
• the suppression element is configured for partly enveloping, in the circumferential direction, a tubular element, in such manner that the suppression element with the inner side is facing the tubular element for forming, in operation, a tube segment, which is extending co-axially round said reference axis, and which can co-axially envelope the tubular element all round as a result of a pre-determined number N of at least two specimens of the suppression element being mutually interconnected in the circumferential direction, so that, when N=2, said tube segment has one, and only one, pair of suppression elements which in said pair are adjacent to one another in the circumferential direction, and when N≥3, said tube segment has N, and only N, pairs of suppression elements which in each pair concerned are adjacent to one another in the circumferential direction;
• said tube segment in the longitudinal direction has an overall length which is equal to the overall length of the suppression element in the longitudinal direction;
• and
• said tube segment is configured for forming, in operation, a tube around the tubular element as a result of multiple specimens of said tube segment being mutually interconnected in the longitudinal direction;
• and
• the suppression element comprises a fin structure, which on said outer side is protruding at least in radial direction relative to said reference axis, and which is configured for reducing, in operation, vorticity shedding at the downstream side of the tubular element;
• wherein:
• the first longitudinal edge comprises at least one first fin longitudinal edge portion, wherein the at least one first fin longitudinal edge portion is extending helically around said reference axis;
• the fin structure comprises a first fin structure, which is extending along and from said at least one first fin longitudinal edge portion, and which on said outer side at said at least one first fin longitudinal edge portion is protruding from said at least one first fin longitudinal edge portion in said radial direction for said reducing of said vorticity shedding;
• the second longitudinal edge comprises at least one second fin longitudinal edge portion, wherein the at least one second fin longitudinal edge portion is extending helically around said reference axis;
• the fin structure comprises a second fin structure, which is extending along and from said at least one second fin longitudinal edge portion, and which on said outer side at said at least one second fin longitudinal edge portion is protruding from said at least one second fin longitudinal edge portion in said radial direction for said reducing of said vorticity shedding;
• and
• the at least one first fin longitudinal edge portion and the at least one second fin longitudinal edge portion of the suppression element are configured such that, for each pair concerned of said one pair of suppression elements or of said N pairs of suppression elements, the at least one first fin longitudinal edge portion of one suppression element of said pair concerned and the at least one second fin longitudinal edge portion of the other suppression element of said pair concerned are lying helically in line relative to one another.