Experimental study on aerodynamic coefficients of yawed cylinders

Hoang, M. C.; Laneville, A.; Légeron, Frédéric

doi:10.1016/j.jfluidstructs.2015.01.002

Cited by 15 publications

(6 citation statements)

References 17 publications

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“…A graphical representation of both U ref and l ref parameters and 55 ○ , the levels of the PSD dropped and the predicted reduced frequencies had arbitrary values. Similar deviations from the independence principle were found in previous studies dealing with the effects of the flow inclination (Lucor and Karniadakis, 2003;Thakur et al, 2004;Hoang et al, 2015;Bourguet and Triantafyllou, 2016;) and with the curvature of the geometry (Gallardo et al, 2014).…”

Section: Results For the Baseline Geometrysupporting

confidence: 85%

Vortex induced vibrations of wind turbine blades: Influence of the tip geometry

et al. 2020

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The present investigation used numerical simulations to study the vortex induced vibrations (VIVs) of a 96 m long wind turbine blade. The results of this baseline shape were compared with four additional geometry variants featuring different tip extensions. The geometry of the tip extensions was generated through the variation of two design parameters: the dihedral angle bending the blade out of the rotor plane and the sweep angle bending the blade in the rotor plane. The applied numerical methods relied on a fluid structure interaction (FSI) approach, coupling a computational fluid dynamics solver with a multi-body structural solver. The methodology followed for locating VIV regions was based on the variation of the inclination angle. This variable was defined as the angle between the freestream velocity and the blade axis, being 0 ○ when these vectors were normal and positive when a velocity component from tip to root was introduced. For the baseline geometry, the FSI simulations predicted significant blade vibrations for inclination angles between 47.5 ○ and 60 ○ with a maximum peak-to-peak amplitude of 2.3 m. The installation of the different tip extensions on the blade geometry was found to significantly modify the inclination angles where VIV was observed. In particular, the simulations of three of the tip designs showed a shifting of several degrees for the point where the maximum vibrations were recorded. For the specific tip geometry where only the sweep angle was taken into account, a total mitigation of the VIV was observed.

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Section: Results For the Baseline Geometrysupporting

confidence: 85%

Vortex induced vibrations of wind turbine blades: Influence of the tip geometry

et al. 2020

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“…0.91 Hz), where maximum VIV are expected. Indeed, the natural frequency of shedding f shnat of an inclined flow with an angle ψ can be related to the Strouhal number St by means of the independence principle, which is valid for small angles [Hoang et al (2015)], as:…”

Section: Results For the Clean Geometrymentioning

confidence: 99%

Suppressing Vortex Induced Vibrations of Wind Turbine Blades with Flaps

Horcas

Madsen

Sørensen

et al. 2019

Springer Tracts in Mechanical Engineering

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“…The authors related the observed inclination angle bounds of instability to limits in the effective velocity characterizing the problem. This was done through the independence principle (Jones, 1947;Lucor and Karniadakis, 2003;Thakur et al, 2004;Hoang et al, 2015;Bourguet and Triantafyllou, 2016; that states that for an inclined inflow the emergence of VIV is steered by the sectional component of the velocity. This confined manifestation of the vibrations in terms of effective wind speed, which is a signature of VIV, was also found in the work of Horcas et al (2019) based on the AVATAR blade.…”

Section: Introductionmentioning

confidence: 99%

Vibrations of wind turbine blades in standstill: Mapping the influence of the inflow angles

et al. 2022

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The present investigation used numerical simulations to study the vibrations of a wind turbine blade in standstill. Such vibrations are presumed to affect horizontal axis wind turbine designs and can jeopardize the structural integrity of the machine. The applied numerical methods relied on a fluid–structure interaction (FSI) approach, coupling a computational fluid dynamics (CFD) solver with a multibody finite-element structural solver. A 96-m-long wind turbine blade was studied for a large parametric space, accounting for the variation of both pitch and inclination. The inclination was defined as the angle between the freestream velocity and the cross-sectional plane at the root, allowing for the introduction of a flow component in the spanwise direction. The pitch variation corresponded to the rotation of the inflow around the spanwise axis, steering the angles of attack seen by the airfoils. Two regimes of vibrations were characterized, depending on the considered range of the inclination angle. For high inclinations, the pitch angles leading to vibrations clustered around a particular region of the parametric space, and the appearance of large oscillations was accompanied by the synchronization of the loading with the frequency of motion. At low inclination angles, the mechanism triggering vibrations was relatively similar, even if the excitation spectrum was richer, and the critical pitch angles seemed to be more scattered. Regardless of the inflow, the problem was highly three-dimensional, and several complex flow phenomena such as oblique shedding and phase dislocations were identified.

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Experimental study on aerodynamic coefficients of yawed cylinders

Cited by 15 publications

References 17 publications

Vortex induced vibrations of wind turbine blades: Influence of the tip geometry

Vortex induced vibrations of wind turbine blades: Influence of the tip geometry

Suppressing Vortex Induced Vibrations of Wind Turbine Blades with Flaps

Vibrations of wind turbine blades in standstill: Mapping the influence of the inflow angles

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