A flexible rod in annular leakage flow: Influence of turbulence and equilibrium offset, and analysis of instability mechanisms

Langthjem, Mikael A.; Morita, Hideyuki; Nakamura, Tomomichi; Nakano, Masami

doi:10.1016/j.jfluidstructs.2006.03.002

Cited by 15 publications

(9 citation statements)

References 28 publications

(68 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is well known that the linear theory of Païdoussis (1973) underestimates the viscous effects in annular flows. The alternative theories (Mateescu and Païdoussis, 1987;Mateescu et al, 1989;Langthjem et al, 2006;Langthjem and Nakamura, 2007;Fujita and Shintani, 2001;Inada and Hayama, 1990) all assume very small flow passages, typically less than 10% of the channel diameter. Consequently, these alternative theories are not applicable as this condition is not fullfilled in this geometry, where P/D o = 1.28.…”

Section: Vibration Characteristicsmentioning

confidence: 99%

Modal characteristics of a flexible cylinder in turbulent axial flow from numerical simulations

Ridder

Degroote

Tichelen

et al. 2013

Journal of Fluids and Structures

View full text Add to dashboard Cite

In this article the vibration behavior of a flexible cylinder subjected to an axial flow is investigated numerically. Therefore a methodology is constructed, which relies entirely on fluid-structure interaction calculations. Consequently, no force coefficients are necessary for the numerical simulations. Two different cases are studied. The first case is a brass cylinder vibrating in an axial water flow. This calculation is compared to experiments in literature and the results agree well. The second case is a hollow steel tube, subjected to liquid lead-bismuth flow. Different flow boundary conditions are tested on this case. Each type of boundary conditions leads to a different confinement and results in different eigenfrequencies and modal damping ratios. Wherever appropriate, a comparison has been made with an existing theory. Generally, this linear theory and the simulations in this article agree well on the frequency of a mode. With respect to damping, the agreement is highly dependent on the correlation used for the normal friction coefficients in the linear theory.

show abstract

Section: Vibration Characteristicsmentioning

confidence: 99%

Modal characteristics of a flexible cylinder in turbulent axial flow from numerical simulations

Ridder

Degroote

Tichelen

et al. 2013

Journal of Fluids and Structures

View full text Add to dashboard Cite

show abstract

“…Several methods to predict the dynamic behavior of the rod subjected to an annular flow have been developed, These include the linearized potential flow theory based model by Mateescu and Paidoussis [1,2] and Mateescu et al [3], and the pressure-loss models by Hobson [4], Fujita et al [5] and Langthjem et al [6]. Recently, Kang et al proposed a theory based on the pressure-loss model with consideration of flow friction [7].…”

Section: Introductionmentioning

confidence: 99%

An experimental investigation on the narrow annular-flow-induced vibration instability of a tube

Kang¹,

Muriethi²,

Pettigrew³

2011

WIT Transactions on the Built Environment

View full text Add to dashboard Cite

The stability of a simply-supported tube subjected to annular flow in a finitelength narrow gap support is experimentally investigated. The exit boundary condition of the annular-leakage passage is known to be a possible cause of instability of the inner tube. In this study, therefore, several finite-length gap supports considering two diffuser angles were investigated on the effects of the annular gap and diffuser angle to the instability of the inner tube. Numerous experiments with the different supports have been performed in a transparent plexiglass tube so that a basic annular-flow can be provided for the inner tube and the movement of the tube can be measured by several laser vibrometers. It is observed that (1) the tube loses stability by flutter at very low flow velocity; the highest critical flow velocity is 3 m/s, (2) the critical flow velocity is strongly dependent on the annular gap size, the diffuser angle and the combination of both, and (3) generally the smaller the gap the lower the critical flow velocity.

show abstract

“…Here the nonconservative fluid forces are associated with the term 3kbq y qh=qy in (17), which acts as a uniformly distributed tangential 'follower' force. [It is shown in Langthjem et al (2006) that flutter instability is possible with both rod ends supported, and that the flutter is a downstream travelling wave.] As the circumferential flow-induced 'elastic foundation' involves only conservative forces, as shown in (20) and (21), it will not enter directly in an energy-based flutter criterion.…”

Section: Flutter Instabilitymentioning

confidence: 99%

“…Tanaka et al (2001) considered a system of connected rigid centre-bodies as a model of a high-speed train in a tunnel. Studies involving a flexible centre-body were carried out by Paı¨doussis and Pettigrew (1979), Paı¨doussis et al (1990), Fujita and Shintani (2001), Fujita et al (2004), and Langthjem et al (2006).…”

Section: Introductionmentioning

confidence: 99%

Influence of swirl on the stability of a rod in annular leakage flow

Langthjem

Nakamura

2007

Journal of Fluids and Structures

Self Cite

View full text Add to dashboard Cite

A flexible rod in annular leakage flow: Influence of turbulence and equilibrium offset, and analysis of instability mechanisms

Cited by 15 publications

References 28 publications

Modal characteristics of a flexible cylinder in turbulent axial flow from numerical simulations

Modal characteristics of a flexible cylinder in turbulent axial flow from numerical simulations

An experimental investigation on the narrow annular-flow-induced vibration instability of a tube

Influence of swirl on the stability of a rod in annular leakage flow

Contact Info

Product

Resources

About