Wave forces acting on a semi-submerged porous circular cylinder

Bao, Weiguang; Kinoshita, Takeshi; Zhao, Fenfang

doi:10.1243/14750902jeme145

Cited by 7 publications

(5 citation statements)

References 10 publications

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“…It was found that the exciting forces on the porous geometries considered were 5-20 times smaller than on their solid body counterparts, whereas the mean drift wave forces on the porous cases were more than four times lower than in the impermeable cases. A single cylindrical body with a porous cover, bottom, and sidewall surfaces was examined in [32,33]. Here, the Haskind relations were applied, and an additional damping coefficient due to the porosity was found.…”

Section: Introductionmentioning

confidence: 99%

Mean Drift Wave Forces on Arrays of Bodies Surrounded by Thin Porous Surfaces

Konispoliatis

Mavrakos

2023

JMSE

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A semi-analytical solution is presented for the evaluation of mean drift wave forces on arrays of structures composed of impermeable vertical cylindrical bodies and surrounded by thin, porous surfaces. The porous cell is assumed to have fine pores so that a linear pressure drop can be considered. The mean drift wave forces on the array are determined via two principally different approaches: the momentum conservation theory and the direct integration of all pressure contributions upon the bodies’ instantaneous wetted surfaces. A solution method that solves the corresponding diffraction problem following the multiple scattering approach is proposed to account for the hydrodynamic interaction phenomena between the waves and the bodies. Numerical results are presented which illustrate the consistency of each of the two approaches in accurately evaluating the mean wave drift forces on several examined array configurations. It is shown that the thin, porous surface significantly reduces the drift forces on the array of bodies, whereas at specific wave frequencies, local enhancements of the forces’ values are noted due to the amplified wave field between the members of the array.

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Section: Introductionmentioning

confidence: 99%

Mean Drift Wave Forces on Arrays of Bodies Surrounded by Thin Porous Surfaces

Konispoliatis

Mavrakos

2023

JMSE

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“…Zhao et al (2007) adopted a lumped-mass model and calculated the hydrodynamic force on a net using the Morison equation. Bao et al (2009) used linear potential theory by applying Darcy's law to a porous boundary and calculated the hydrodynamic force on a net cage using the eigenfunction expansion method. Patursson et al (2010) investigated the flow characteristics through and around a net panel through computational fluid dynamics (CFD) and laboratory measurements.…”

Section: Introductionmentioning

confidence: 99%

Wave diffraction of a hybrid wind turbine foundation with a double-layer aquaculture cage

Zhu

Dong

et al. 2022

Front. Mar. Sci.

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A hybrid wind turbine foundation combined with a double-layer offshore net cage for marine aquaculture is proposed in this paper. To study the diffraction and hydrodynamic loads on the structure for waves with small steepness, a numerical model was established using linear potential theory and solved using the eigenfunction expansion method. A porosity parameter was introduced to describe the hydrodynamic characteristics of the net panels. The model was validated based on existing numerical results and experimental data. An empirical formula was derived to calculate the porosity parameter based on the opening ratios of the nets. The wavefield and wave force were calculated and analyzed by setting different porosity parameters, spacings between the exterior net and interior net, radius ratios of the exterior net to the wind turbine tower and thicknesses of the friction wheel. Noticeable differences in the wave elevation were observed between the upstream and downstream sides of the nets. At downstream sites, the wavefield exhibits different profiles, particularly for structures with low porosities. Sloshing modes were observed that impacted the force and wave elevation at certain frequencies. For the common fishing nets with large porosities, the spacing between the nets does not have a significant impact on the wavefield and wave force acting on the structure. Moreover, the radius and thickness of the friction wheel have a non-negligible influence on the force acting on the structure, which also narrows the intervals between adjacent sloshing frequencies. In summary, this study provides a perspective for the engineering design and hydrodynamic analysis of a hybrid wind turbine foundation with a double-layer aquaculture cage.

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“…Comparisons between experimental and numerical results were presented in [28] concerning the diffraction of linear waves around a group of dual porous cylinders, and in [29] regarding the hydrodynamics of a bottom seated impermeable cylinder encircled by a porous cylindrical surface. A semi-submerged porous circular cylinder was examined in [30] by means of the eigenfunction expansion. Applying the Haskind relations, a new component of damping was found, caused by the porosity in addition to the conventional wave radiating damping.…”

Section: Introductionmentioning

confidence: 99%

Theoretical Hydrodynamic Analysis of a Surface-Piercing Porous Cylindrical Body

Konispoliatis

Chatjigeorgiou

Mavrakos

2021

Fluids

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In the present study, the diffraction and the radiation problems of water waves by a surface-piercing porous cylindrical body are considered. The idea conceived is based on the capability of porous structures to dissipate the wave energy and to minimize the environmental impact, developing wave attenuation and protection. In the context of linear wave theory, a three-dimensional solution based on the eigenfunction expansion method is developed for the determination of the velocity potential of the flow field around the cylindrical body. Numerical results are presented and discussed concerning the wave elevation and the hydrodynamic forces on the examined body for various values of porosity coefficients. The results revealed that porosity plays a key role in reducing/controlling the wave loads on the structure and the wave run-up, hence porous barriers can be set up to protect a marine structure against wave attack.

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Wave forces acting on a semi-submerged porous circular cylinder

Cited by 7 publications

References 10 publications

Mean Drift Wave Forces on Arrays of Bodies Surrounded by Thin Porous Surfaces

Mean Drift Wave Forces on Arrays of Bodies Surrounded by Thin Porous Surfaces

Wave diffraction of a hybrid wind turbine foundation with a double-layer aquaculture cage

Theoretical Hydrodynamic Analysis of a Surface-Piercing Porous Cylindrical Body

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