Browsing by Author "Varghese, A."

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    Wave attenuation due to stratified porous structure in the presence of stepped seabed
    (Springer Nature, 2024) Varghese, A.; Krishna, K.R.A.; Karmakar, D.
    The wave transformation due to the stratified porous structures in the presence of stepped seabed at leeward side is analysed based on the small amplitude wave theory. The study is performed to analyse the effectiveness of both horizontal and vertical stratified porous structure for the wave attenuation in the nearshore regions using orthogonal mode-coupling relation and eigenfunction expansion method. The hydrodynamic coefficients such as wave reflection, transmission, dissipation, wave force acting and surface elevation are investigated for both horizontally and vertically stratified porous structures. The effect of change in the structural properties such as varying porosity, friction factor, structural width, angle of incidence and length between the porous structure and stepped seabed are examined. Thereafter, the comparative study is performed for both horizontally and vertically stratified porous structure in the presence of stepped seabed and the numerical results are validated with the results available in the literature. The present study illustrates that with the increase in step height, the wave damping efficiency is enhanced. In addition, the wave energy dissipation is observed more for horizontally stratified structure in the case of longer waves whereas vertically stratified structure is effective in dampening of shorter waves. Further, the wave reflection and transmission for vertically stratified structure is found to be more for same length between structure and stepped seabed. The stepped seabed in leeward side in combination with vertical and horizontal stratified porous structure is intended to be an effective solution for protection of coastal facility. © The Author(s), under exclusive licence to Sociedade Brasileira de Engenharia Naval 2024.
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    Wave Attenuation due to Stratified Porous Structure with Stepped Seabed
    (Editorial Board of Journal of Harbin Engineering, 2024) Varghese, A.; Athul Krishna, K.R.; Karmakar, D.
    The wave interaction with stratified porous structure combined with a surface-piercing porous block in a stepped seabed is analysed based on the small amplitude wave theory. The study is performed to analyse the effectiveness of partial porous structure in increasing the wave attenuation in the nearshore regions consisting of stratified porous structures of different configurations using the eigenfunction expansion method and orthogonal mode-coupling relation. The hydrodynamic characteristics such as wave reflection coefficient, transmission coefficient, dissipation coefficient, wave force impact and surface elevation are investigated due to the presence of both horizontally and vertically stratified porous structures. The effect of varying porosity, structural width, angle of incidence, wavelength and length between the porous block and stratified structure is examined. The numerical results are validated with the results available in the literature. The present study illustrates that the presence of the stratified structure decreases wave transmission and efficient wave attenuation can also be easily achieved. The wave force acting on stratified structure can be decreased if the structure is combined with wider surface-piercing porous blocks. Further, the presence of stratified porous structure combined with porous block helps in creating a tranquil zone in the leeside of the structure. The combination of vertical and horizontal stratified porous structure with surface-piercing porous block is intended to be an effective solution for the protection of coastal facilities. © Harbin Engineering University and Springer-Verlag GmbH Germany, part of Springer Nature 2024.