An aeroelastic model for vortex-induced vibrating cylinders subject to frequency lock-in

• Published in: Journal of fluids and structures Vol. 61; pp. 42 - 59
• Main Authors: Besem, Fanny M., Thomas, Jeffrey P., Kielb, Robert E., Dowell, Earl H.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-02-2016
• Subjects: Aeroelastic model; Computational fluid dynamics; Cylinders; Degrees of freedom; Fluid flow; Frequency lock-in; Harmonic balance; Mathematical analysis; Mathematical models; Shedding; Vortex-induced vibration; Vortices; Aeroelastic model; Frequency lock-in; Harmonic balance; Vortex-induced vibration
• ISSN: 0889-9746; 1095-8622
• DOI: 10.1016/j.jfluidstructs.2015.10.009

This work presents a novel way to calculate the response amplitude of an elastically supported cylinder experiencing vortex-induced vibrations. The method couples a computational fluid dynamic (CFD) model of the shedding vortex flow to a structural model representation of the elastically supported cylinder. The aerodynamic forces on the cylinder are calculated using a harmonic balance, frequency domain solver. Three cases are considered: the cylinder vibrating transverse to the flow, in-line with the flow, and with both degrees of freedom. Two shedding patterns are observed, symmetric and antisymmetric, depending on the lock-in region considered. The in-line degree of freedom does not have a significant effect on the cylinder cross-flow response, except for very low mass or very low damping.
•We characterized the shedding patterns for transverse and in-line lock-in regions.•We used a fluid-structure interaction model with a frequency domain CFD code.•The transverse lock-in region is more accurately captured and matches experiments.•The in-line amplitude is insignificant except at very low mass and damping.•For very low mass ratios, it is necessary to model both degrees of freedom.