Characteristics of fluid dynamic forces acting on a circular cylinder oscillated in the streamwise direction and its wake patterns

T. Nishihara, Shigehiko Kaneko, T. Watanabe

Research output: Contribution to journalArticle

60 Citations (Scopus)

Abstract

This paper describes the characteristics of fluid forces and wake patterns of a circular cylinder oscillating in the streamwise direction in a cross-flow, on the basis of precise measurements and flow-visualizations in forced-oscillation tests in a water tunnel at subcritical Reynolds numbers. The added mass and added damping coefficients of a circular cylinder in a streamwise oscillation were calculated. The results of the forced-oscillation tests confirmed that two reduced-velocity ranges with negative added damping exist. The two ranges agree well with the two streamwise excitation regions observed in the free-oscillation tests in several previous studies. The added mass coefficient for the streamwise vibration varies greatly, depending on the reduced velocity, and that can affect the dynamic behavior of the streamwise vibration under low mass-ratio conditions. Furthermore, the mean drag coefficient attains its maximum at the reduced velocity between the first and second excitation regions where the added damping coefficient reaches its local maximum. This suggests that the increase in the mean drag coefficient induced by the formation of alternate vortices magnifies the fluid damping effect and contributes to the damping region between the first and second excitation region.

Original languageEnglish
Pages (from-to)505-518
Number of pages14
JournalJournal of Fluids and Structures
Volume20
Issue number4 SPEC. ISS.
DOIs
Publication statusPublished - 2005 Jan 1
Externally publishedYes

Fingerprint

Circular cylinders
Fluid dynamics
Damping
Drag coefficient
Fluids
Flow visualization
Tunnels
Vortex flow
Reynolds number
Water

ASJC Scopus subject areas

  • Mechanical Engineering

Cite this

Characteristics of fluid dynamic forces acting on a circular cylinder oscillated in the streamwise direction and its wake patterns. / Nishihara, T.; Kaneko, Shigehiko; Watanabe, T.

In: Journal of Fluids and Structures, Vol. 20, No. 4 SPEC. ISS., 01.01.2005, p. 505-518.

Research output: Contribution to journalArticle

@article{d64b166b70be41c4a4b0d157a6264aa7,
title = "Characteristics of fluid dynamic forces acting on a circular cylinder oscillated in the streamwise direction and its wake patterns",
abstract = "This paper describes the characteristics of fluid forces and wake patterns of a circular cylinder oscillating in the streamwise direction in a cross-flow, on the basis of precise measurements and flow-visualizations in forced-oscillation tests in a water tunnel at subcritical Reynolds numbers. The added mass and added damping coefficients of a circular cylinder in a streamwise oscillation were calculated. The results of the forced-oscillation tests confirmed that two reduced-velocity ranges with negative added damping exist. The two ranges agree well with the two streamwise excitation regions observed in the free-oscillation tests in several previous studies. The added mass coefficient for the streamwise vibration varies greatly, depending on the reduced velocity, and that can affect the dynamic behavior of the streamwise vibration under low mass-ratio conditions. Furthermore, the mean drag coefficient attains its maximum at the reduced velocity between the first and second excitation regions where the added damping coefficient reaches its local maximum. This suggests that the increase in the mean drag coefficient induced by the formation of alternate vortices magnifies the fluid damping effect and contributes to the damping region between the first and second excitation region.",
author = "T. Nishihara and Shigehiko Kaneko and T. Watanabe",
year = "2005",
month = "1",
day = "1",
doi = "10.1016/j.jfluidstructs.2005.02.003",
language = "English",
volume = "20",
pages = "505--518",
journal = "Journal of Fluids and Structures",
issn = "0889-9746",
publisher = "Academic Press Inc.",
number = "4 SPEC. ISS.",

}

TY - JOUR

T1 - Characteristics of fluid dynamic forces acting on a circular cylinder oscillated in the streamwise direction and its wake patterns

AU - Nishihara, T.

AU - Kaneko, Shigehiko

AU - Watanabe, T.

PY - 2005/1/1

Y1 - 2005/1/1

N2 - This paper describes the characteristics of fluid forces and wake patterns of a circular cylinder oscillating in the streamwise direction in a cross-flow, on the basis of precise measurements and flow-visualizations in forced-oscillation tests in a water tunnel at subcritical Reynolds numbers. The added mass and added damping coefficients of a circular cylinder in a streamwise oscillation were calculated. The results of the forced-oscillation tests confirmed that two reduced-velocity ranges with negative added damping exist. The two ranges agree well with the two streamwise excitation regions observed in the free-oscillation tests in several previous studies. The added mass coefficient for the streamwise vibration varies greatly, depending on the reduced velocity, and that can affect the dynamic behavior of the streamwise vibration under low mass-ratio conditions. Furthermore, the mean drag coefficient attains its maximum at the reduced velocity between the first and second excitation regions where the added damping coefficient reaches its local maximum. This suggests that the increase in the mean drag coefficient induced by the formation of alternate vortices magnifies the fluid damping effect and contributes to the damping region between the first and second excitation region.

AB - This paper describes the characteristics of fluid forces and wake patterns of a circular cylinder oscillating in the streamwise direction in a cross-flow, on the basis of precise measurements and flow-visualizations in forced-oscillation tests in a water tunnel at subcritical Reynolds numbers. The added mass and added damping coefficients of a circular cylinder in a streamwise oscillation were calculated. The results of the forced-oscillation tests confirmed that two reduced-velocity ranges with negative added damping exist. The two ranges agree well with the two streamwise excitation regions observed in the free-oscillation tests in several previous studies. The added mass coefficient for the streamwise vibration varies greatly, depending on the reduced velocity, and that can affect the dynamic behavior of the streamwise vibration under low mass-ratio conditions. Furthermore, the mean drag coefficient attains its maximum at the reduced velocity between the first and second excitation regions where the added damping coefficient reaches its local maximum. This suggests that the increase in the mean drag coefficient induced by the formation of alternate vortices magnifies the fluid damping effect and contributes to the damping region between the first and second excitation region.

UR - http://www.scopus.com/inward/record.url?scp=20344393102&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=20344393102&partnerID=8YFLogxK

U2 - 10.1016/j.jfluidstructs.2005.02.003

DO - 10.1016/j.jfluidstructs.2005.02.003

M3 - Article

VL - 20

SP - 505

EP - 518

JO - Journal of Fluids and Structures

JF - Journal of Fluids and Structures

SN - 0889-9746

IS - 4 SPEC. ISS.

ER -