Structural performance of a submerged bottom-mounted compound porous cylinder on the water wave interaction in the presence of a porous sea-bed

Abstract

The scattering problem of a submerged bottom-mounted compound porous cylinder located on a porous sea-bed is theoretically investigated under the assumption of linear potential flow theory. The compound cylinder is comprised of an impermeable inner cylinder and a porous outer cylinder. The boundary conditions on the porous boundaries follow Darcy's law by assuming fine pores in the porous structure. The whole fluid region is split into three bounded and an unbounded sub-regions, within which the individual velocity potentials are found by using eigenfunction expansion technique. Further, utilization of the matching conditions along the boundaries of individual successive regions leads to a semi-analytical solution of the proposed problem. The impact of the non-dimensional porous-effect parameter of the cylindrical wall, the draft ratio, radius ratio and the sea-bed porosity on waveloads and free-surface elevation are studied. In addition, the wave power dissipation for the system is calculated by integrating the power absorbed by outer cylinder porous wall via direct method. Also, the far-field scattering coefficients are obtained with the help of asymptotic forms of Hankel functions in the plane wave representation form. Numerical results for the far-field scattering coefficient and power dissipation are investigated for various parameters. The theoretical model is verified by comparing it with the results of the conventional analytical work and the experimental work. The results show that suitable consideration of porosity and structure parameters enhance the efficiency of the proposed compound cylinder in mitigating wave impact.

Wave blocking and Bragg resonance in two-layer fluid with current and surface tension.

“…The theoretical study of the scattering of water waves by different structures such as rigid barriers, porous barriers, elastic plates, caisson etc involves several interesting and important concepts of mathematical analysis and physics of flow of potential kind which have been developed over the last few decades. Water wave scattering in single-layer fluid, based on linear theory, has been developed by numerous researchers ( [16], [19], [32] and the references cited there in) over the years due to its potential uses in identifying how a wave is diffracted by the presence of any obstacle. To investigate the influence of surface tension on progressive waves caused by vertical wave producers, Rhodes-Robinson [29] devised an effective reduction approach.…”

Internal shear layer and vortex shedding development of a structured porous coated cylinder using tomographic particle image velocimetry

“…Some practical examples include cylindrical sections of high-speed train pantographs (Sueki, Ikeda & Takaishi 2009; Willmarth & Wei 2021), aircraft landing gear (Boorsma et al. 2009; Geyer 2022 b ), electrical power lines (Blevins 1984), chimney stacks (Zdravkovich 1981), submerged pylons (Sarkar & Chanda 2022) and offshore wind turbine towers (Youssef et al. 2022).…”