Examinando por Autor "Souto Iglesias, A."

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A particle image velocimetry investigation of the flow field close to a heave plate for models of different scales
(Elsevier, 2022-11-08) Saettone, Simone; Molinelli Fernández, E.; Soriano Gómez, C.; Saavedra Ynocente, Leandro; Duque Campayo, D.; Souto Iglesias, A.; Marón Loureiro, Adolfo; Agencia Estatal de Investigación (AEI)
Semi-submersible floating wind turbines are generally equipped with heave plates to introduce additional hydrodynamic damping and decrease the platform’s natural frequency. Scale effects are one of the most critical problems concerning the accuracy of model-scale experiments on these damping-augmenting devices. The current research aimed to assess the impact of the scale factor on the flow physics of oscillating circular solid plates. Forced oscillation flow visualisation model-scale experiments were performed on three geometrically similar one-leg columns of a semi-submersible platform equipped with a circular solid flat heave plate. The forced oscillation tests were performed in the range of extreme and operational Keulegan–Carpenter numbers (KCs) for two different frequencies of the heave plate’s oscillatory motion. A submersible two-dimensional (2D) three-component (3C) Stereoscopic Particle Image Velocimetry (Stereo-PIV) system was employed to measure the flow field velocity distribution. The Stereo-PIV images were obtained at four positions in the oscillation cycle. The investigation focused on detecting scale effects on the velocity and vorticity for the three models of different scales. Similarities in centre positions, shape, and contours between the three models were visualised for the measured velocity field. The computed vorticity field also revealed similarities in centre positions, shape, and contours among the three different scales. Following up on previous works focusing on the hydrodynamic forces on oscillating circular solid plates, the outcomes of this paper also confirm that, for the considered case study, the correct choice of the motion amplitude (KC) impacts the flow physics of the model tests more than the scale factor.
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Scale Effects in Heave Plates: PIV Investigation
(ASME, 2020) Anglada Revenga, E.; Bezunartea Barrio, A.; Marón Loureiro, Adolfo; Molinelli Fernández, E.; Oria Escudero, J.; Saavedra Ynocente, Leandro; Soriano Gómez, C.; Duque Campayo, D.; Gómez Goni, J.; Souto Iglesias, A.
Bezunartea et al. Scale Effects on Heave Plates for Semi-Submersible Floating Offshore Wind Turbines: Case Study With a Solid Plain Plate (Journal of Offshore Mechanics and Arctic Engineering, Vol. 11, pp 1–14, 2019) studied scale effects on the hydrodynamics of heave plates by conducting model scale experimental tests. Three models with different scales of one leg of the HiPRWind platform, equipped with a plain heave plate, were built and tested with forced harmonic heave motions. They showed that the influence of the model scale on the coefficients is clearly weaker than that of the heave motion amplitude. Among the pending tasks in that work was to conduct velocity field measurements of the flow with Particle Image Velocimetry techniques (PIV). This paper discusses some of the results of such measurements, carried out forcing vertical harmonic motions. In these measurements, it is assessed how significant scale effects are also in the local kinematics of the flow, thus complementing the global ones carried out in the referred work. From velocity and vorticity graphs, the flows show great similarities across the three scales, consistent with the ones found in the prequel paper. A metric has been developed whose outcomes are aligned with these results but further work is necessary to develop key indicators to compare flow fields from PIV across different scales.
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Scale Effects on Heave Plates for Semi-Submersible Floating Offshore Wind Turbines: Case Study With a Solid Plain Pla
(ASME, 2019-01-28) Bezunartea Barrio, A.; Fernández Ruano, S.; Marón Loureiro, Adolfo; Molinelli Fernández, E.; Moreno Burón, F.; Oria Escudero, J.; Ríos Tubio, J.; Soriano Gómez, C.; López Pavón, C.; Souto Iglesias, A.; Valea Peces, Álvaro
In the case of SPAR or semi-submersible platforms for floating wind turbines, it is beneficial in some cases to use heave plates that reduce their heave motion amplitude and/or tune their heave natural period. As part of the Hiprwind project, it was decided to study scale effects on the hydrodynamics of this element. To this aim, models of one leg of the platform, equipped with a heave plate without any reinforcements, were built. This model is a simplified representation of the actual one, which incorporates a vertical flap on the heave plate edge. The scales were 1:20, 1:27.6, and 1:45.45, with the former leading to added mass values of the order of 300 kg, becoming one of the largest models for which experiments with heave oscillations have been carried out. Decay tests starting from various amplitudes and forced oscillations tests for a range of frequencies and amplitudes were performed. It is shown in the paper that the influence of the scale factor on the hydrodynamic coefficients is weaker than the effect that the motion amplitude (characterized with the Keulegan–Carpenter (KC) number produces in them. This result is relevant because the selection of a representative KC is an important and somewhat arbitrary aspect to be set in the linear potential simulation codes in order to add viscous damping. What has been shown herein is that a right selection of KC has a larger impact on the models than the uncertainties due to eventual scale effects in the heave-plates dynamics.