Experimental investigation on the mechanism of VIV reduction using helical strakes

Siti Fatin Mohd Razali, Tongming Zhou, Liang Cheng

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)

Abstract

In this study, the mechanism of vortex-induced vibration (VIV) mitigation using helical strakes is further investigated complying with the recent literatures. A rigid circular cylinder of diameter d = 80 mm attached with three-strand helical strakes of a dimension of 10d in pitch and 0.12d in height was tested in a wind tunnel. A bare cylinder was also tested to provide a benchmark for the straked cylinder system. It was found that the helical strakes reduce VIV by about 98%. Unlike the bare cylinder which experiences lock-in over the reduced velocity of 5∼9, the straked cylinder does not show any lock-in region. In exploring the mechanism of VIV reduction by helical strakes, it was found that vortices shed from the straked cylinder are weakened significantly. The cross-correlation coefficients in the bare cylinder wake were much larger than that obtained in the straked cylinder wake, indicating that the correlation length of the former is larger than that of the latter. As a result, the straked cylinder wake agrees more favorably with isotropy than the bare cylinder wake.

Original languageEnglish
Title of host publicationProceedings of the International Offshore and Polar Engineering Conference
Pages1157-1164
Number of pages8
Volume3
Publication statusPublished - 2010
Externally publishedYes
Event20th International Offshore and Polar Engineering Conference, ISOPE-2010 - Beijing
Duration: 20 Jun 201025 Jun 2010

Other

Other20th International Offshore and Polar Engineering Conference, ISOPE-2010
CityBeijing
Period20/6/1025/6/10

Fingerprint

Vortex flow
Circular cylinders
Wind tunnels

ASJC Scopus subject areas

  • Energy Engineering and Power Technology
  • Mechanical Engineering
  • Ocean Engineering

Cite this

Mohd Razali, S. F., Zhou, T., & Cheng, L. (2010). Experimental investigation on the mechanism of VIV reduction using helical strakes. In Proceedings of the International Offshore and Polar Engineering Conference (Vol. 3, pp. 1157-1164)

Experimental investigation on the mechanism of VIV reduction using helical strakes. / Mohd Razali, Siti Fatin; Zhou, Tongming; Cheng, Liang.

Proceedings of the International Offshore and Polar Engineering Conference. Vol. 3 2010. p. 1157-1164.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Mohd Razali, SF, Zhou, T & Cheng, L 2010, Experimental investigation on the mechanism of VIV reduction using helical strakes. in Proceedings of the International Offshore and Polar Engineering Conference. vol. 3, pp. 1157-1164, 20th International Offshore and Polar Engineering Conference, ISOPE-2010, Beijing, 20/6/10.
Mohd Razali SF, Zhou T, Cheng L. Experimental investigation on the mechanism of VIV reduction using helical strakes. In Proceedings of the International Offshore and Polar Engineering Conference. Vol. 3. 2010. p. 1157-1164
Mohd Razali, Siti Fatin ; Zhou, Tongming ; Cheng, Liang. / Experimental investigation on the mechanism of VIV reduction using helical strakes. Proceedings of the International Offshore and Polar Engineering Conference. Vol. 3 2010. pp. 1157-1164
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