On the efficacy of mechanical damping and frequency detuning in alleviating wake-induced flutter of overhead power conductors

Price, S.J.; Abdallah, Riyadh A.

doi:10.1016/0889-9746(90)90029-5

Cited by 7 publications

(4 citation statements)

References 10 publications

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“…As the cylinders vibrate, the vortex path between the cylinders elongates, resulting in a more antiphase nature of the fluid forces. This phenomenon is similar to ‘modal decoupling’, reported by Price & Abdallah (1990), that leads to FIV suppression even if the excitation frequency is closer to the cylinder's natural frequency. In this context, previous studies on rigidly coupled two tandem cylinders have realized , similar to Case 2.…”

Section: Characteristics Of Cylinder Vibrationssupporting

confidence: 85%

“…Further, a rigid coupling modifies φ y12 , leading to modified flow forces on cylinders. Thus, the complexity of the FIV system would increase significantly if the coupling between the cylinders is elastic, and is adequately demonstrated in an FIV study on in-line cylinders by King & Johns (1976) and an associated quasisteady analysis (Price & Abdallah 1990).…”

Section: Scope Of the Present Studymentioning

confidence: 97%

“…The fluid flow is governed by unsteady, incompressible and viscous Navier-Stokes equations, written in non-dimensional form as follows: We consider the dynamics of two elastically mounted circular cylinders in a tandem arrangement, as shown in figure 1. This set-up is a simplified version of Price & Abdallah (1990) for modelling FIV response of electrical conductor wires separated by elastic spacers. Here we consider cross-flow vibrations of cylinders with 1-DOF with equal mass ratio m and zero damping.…”

Section: Governing Equationsmentioning

confidence: 99%

“…In one of the earlier studies, King & Johns (1976) observed a delayed vibration response for an in-phase motion of elastically coupled tandem cylinders at . Further, Price & Abdallah (1990) modelled the 2-DOF tandem cylinder system using elastic coupling between them and proposed a frequency detuning technique for undamped FIV suppression. Brika & Laneville (1997) investigated the in-phase and out-of-phase motion (controlled through mechanical linkages) FIV of tandem cylinders with for a gap ratio of in an flow.…”

Section: Introductionmentioning

confidence: 99%

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Flow-induced vibrations of elastically coupled tandem cylinders

Sharma,

Bhardwaj

2023

J. Fluid Mech.

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We numerically study the transverse flow-induced vibration (FIV) of elastically coupled tandem cylinders at Reynolds number $100$ , using an in-house immersed boundary method-based solver in two-dimensional coordinates. While several previous studies considered tandem cylinders coupled through flow between them, a hitherto unexplored elastic coupling with fluid flow between them significantly influences FIV. We consider a wide range of gap ratio, reduced velocity, an equal mass ratio of both cylinders and zero damping. A systematic comparison between the classic elastically mounted tandem cylinders and elastically coupled cylinders is presented. The latter configuration exhibits two vibration modes, in-phase and out-of-phase, with corresponding natural frequencies approaching the Strouhal frequency of the system. We quantify variation of the following output variables with reduced velocity and gap ratios: cylinders’ displacement; fluid forces; amplitude spectral density of displacement and force signals; phase characteristics; energy harvesting potential; and discuss the wake characteristics using flow separation, pressure distribution, gap flow quantification, and dynamic mode decomposition characterization. The FIV response is classified into several regimes: initial desynchronization with and without gap vortices; final desynchronization; mixed mode; initial branch; lock-in; upper and lower branch; wake-induced vibration; galloping. We draw upon similarities of computed FIV characteristics with those of an isolated cylinder, in which the lower branch exhibits larger a amplitude than the upper branch. The elastically coupled cylinders show a galloping response similar to an isolated D-section cylinder. By invoking the elastic coupling, we demonstrate FIV suppression and augmentation for in-phase and out-of-phase systems. Our calculations show larger energy harvesting potential at reduced cost for elastically coupled cylinders.

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Section: Characteristics Of Cylinder Vibrationssupporting

confidence: 85%

Section: Scope Of the Present Studymentioning

confidence: 97%

Section: Governing Equationsmentioning

confidence: 99%