Linear and Nonlinear Dynamics of Cantilevered Cylinders in Axial Flow. Part 3: Nonlinear Dynamics

Semler, C.; Lopes, Joseph L.; Augu, N.; Paı̈doussis, M.P.

doi:10.1006/jfls.2002.0445

Cited by 69 publications

(41 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…with a well streamlined end, yields distinct results depending on the length ℓ, figure 3(b). For short cylinders, ℓ ≪ 1, the divergence and flutter limits decrease with ℓ in a manner similar to that of the previous case, as could be predicted from the results of Semler et al (2002) (v =1.79/ℓ for divergence, v =4.72/ℓ for flutter). However, for long cylinders, divergence and flutter persist, in contrast to the previous case with f =0.5.…”

Section: 2supporting

confidence: 83%

“…The cylinder is modelled as a beam (with flexural rigidity set to zero in some cases), coupled with the fluid dynamics via inviscid terms (Lighthill 1960), friction and specific models of the flow-induced forces at the trailing end. Prediction of divergence and flutter using this model were found to be in good agreement with experiments in Semler et al (2002). Further refinements, including accounting for nonlinear effects, showed that the linear approach was robust, at least for the first instabilities encountered: divergence occurs in a supercritical form and is followed by flutter.…”

Section: Introductionsupporting

confidence: 53%

“…Both divergence and flutter results for long cylinders are confirmed by converged Galerkin computations at ℓ =4.4 using 12 modes. Note that above ℓ = 1 ,fl u t t e rb e c o m e so ft h eP ä ıdoussis type as was hypothesized by Semler et al (2002).…”

Section: 2mentioning

confidence: 79%

“…Effect of length on stability 3.1. Previous results We summarize some results obtained by Semler et al (2002), where equation (2.16) has been solved for several values of f , c N /c T , εc T , with the mass parameter β being fixed at 0.47 which is close to neutral buoyancy (β =0.5). The relation between c b and f , the two coefficients related to the shape of the downstream end, was set to c b =1− f .…”

Section: Solution Proceduresmentioning

confidence: 88%

“…In this problem, the dominant nonlinear terms are associated with geometric effects, when the fluid forces are applied on the instantaneous deformed position of the cylinder. The corresponding set of equations has been derived by Lopes, Païdoussis & Semler (2002).…”

Section: Nonlinear Modelmentioning

confidence: 99%

See 4 more Smart Citations

Flutter of long flexible cylinders in axial flow

et al. 2007

View full text Add to dashboard Cite

We consider the stability of a thin flexible cylinder considered as a beam, when subjected to axial flow and fixed at the upstream end only. A linear stability analysis of transverse motion aims at determining the risk of flutter as a function of the governing control parameters such as the flow velocity or the length of the cylinder. Stability is analysed applying a finite-difference scheme in space to the equation of motion expressed in the frequency domain. It is found that, contrary to previous predictions based on simplified theories, flutter may exist for very long cylinders, provided that the free downstream end of the cylinder is well-streamlined. More generally, a limit regime is found where the length of the cylinder does not affect the characteristics of the instability, and the deformation is confined to a finite region close to the downstream end. These results are found complementary to solutions derived for shorter cylinders and are confirmed by linear and nonlinear computations using a Galerkin method. A link is established to similar results on long hanging cantilevered systems with internal or external flow. The limit case of vanishing bending stiffness, where the cylinder is modelled as a string, is analysed and related to previous results. Comparison is also made to existing experimental data, and a simple model for the behaviour of long cylinders is proposed.

show abstract

Section: 2supporting

confidence: 83%

Section: Introductionsupporting

confidence: 53%

Section: 2mentioning

confidence: 79%

Section: Solution Proceduresmentioning

confidence: 88%

Section: Nonlinear Modelmentioning

confidence: 99%

See 3 more Smart Citations

Flutter of long flexible cylinders in axial flow

et al. 2007

View full text Add to dashboard Cite

show abstract

Linear and Nonlinear Dynamics of Cantilevered Cylinders in Axial Flow. Part 1: Physical Dynamics

Paı̈doussis

Grinevich

ADAMOVIC

et al. 2002

Journal of Fluids and Structures

Self Cite

View full text Add to dashboard Cite

This paper is the first in a three-part study of the dynamics of cantilevered cylinders in axial flow. After an extensive literature review, the physical dynamics of the system is examined; specifically (a) the experimental behaviour of elastomer cylinders in water flow, and (b) the energy transfer mechanisms, discussed from a work-energy perspective without solving the equations of motion. In general, the system loses stability by divergence and, as the flow velocity is increased, it is subject to second-and third-mode flutter, provided that the free end is well-streamlined; if, however, the free end is blunt, these instabilities do not occur. Oscillations are generally three-dimensional (orbital). The experimental observations are in good qualitative agreement with those expected from the energy transfer analysis, and in reasonably good quantitative agreement with solutions of the linearized equation of motion (obtained from Part 3 of this study). For some shapes of the free-end, resonances are observed with a fairly constant Strouhal number.

show abstract