Effect of porosity on an internal solitary wave propagating over a porous trapezoidal obstacle

Ming Hung Cheng; Chih Min Hsieh; John R C Hsu; Robert R. Hwang

doi:10.1016/j.oceaneng.2016.11.067

Effect of porosity on an internal solitary wave propagating over a porous trapezoidal obstacle

Ming Hung Cheng, Chih Min Hsieh, John R C Hsu, Robert R. Hwang

Research output: Contribution to journal › Article › peer-review

4 Citations (Scopus)

Abstract

A permeable seabed may influence the evolution of an internal solitary wave propagating on a continental shelf and nearshore. In order to study the porous effect, numerical simulations are performed to investigate the flow field and waveform inversion of a large depression ISW propagating over a porous trapezoidal obstacle. A finite volume based Cartesian grid method is adopted to solve the Reynolds averaged Navier-Stokes equations using a k-ε model for the turbulent closure and porous media model together. Numerical results reveal that waveform inversion weakens significantly, as the porosity of the obstacle increases, except when porosity n_f<0.2. At the same time, the magnitude of vorticity and turbulent energy decrease remarkably due to acute reduction of the production term induced by percolation and wave-pore interaction. Moreover, a skewed hump shaped relation appears between the maximum vorticity and the porosity. For transmitted wave energy on a horizontal plateau, total energy may decrease as n_f<0.2 but increases moderately while n_f>0.2 during a strong wave-obstacle interaction.

Original language	English
Pages (from-to)	126-141
Number of pages	16
Journal	Ocean Engineering
Volume	130
DOIs	https://doi.org/10.1016/j.oceaneng.2016.11.067
Publication status	Published - 15 Jan 2017

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@article{639a79c2189a44d6ade4ffdd29cf1095,

title = "Effect of porosity on an internal solitary wave propagating over a porous trapezoidal obstacle",

abstract = "A permeable seabed may influence the evolution of an internal solitary wave propagating on a continental shelf and nearshore. In order to study the porous effect, numerical simulations are performed to investigate the flow field and waveform inversion of a large depression ISW propagating over a porous trapezoidal obstacle. A finite volume based Cartesian grid method is adopted to solve the Reynolds averaged Navier-Stokes equations using a k-ε model for the turbulent closure and porous media model together. Numerical results reveal that waveform inversion weakens significantly, as the porosity of the obstacle increases, except when porosity nf<0.2. At the same time, the magnitude of vorticity and turbulent energy decrease remarkably due to acute reduction of the production term induced by percolation and wave-pore interaction. Moreover, a skewed hump shaped relation appears between the maximum vorticity and the porosity. For transmitted wave energy on a horizontal plateau, total energy may decrease as nf<0.2 but increases moderately while nf>0.2 during a strong wave-obstacle interaction.",

keywords = "Internal solitary wave, k-ε turbulent model, Permeable obstacle, RANS equation",

author = "Cheng, {Ming Hung} and Hsieh, {Chih Min} and Hsu, {John R C} and Hwang, {Robert R.}",

year = "2017",

month = jan,

day = "15",

doi = "10.1016/j.oceaneng.2016.11.067",

language = "English",

volume = "130",

pages = "126--141",

journal = "Ocean Engineering",

issn = "0029-8018",

publisher = "Pergamon",

}

TY - JOUR

T1 - Effect of porosity on an internal solitary wave propagating over a porous trapezoidal obstacle

AU - Cheng, Ming Hung

AU - Hsieh, Chih Min

AU - Hsu, John R C

AU - Hwang, Robert R.

PY - 2017/1/15

Y1 - 2017/1/15

N2 - A permeable seabed may influence the evolution of an internal solitary wave propagating on a continental shelf and nearshore. In order to study the porous effect, numerical simulations are performed to investigate the flow field and waveform inversion of a large depression ISW propagating over a porous trapezoidal obstacle. A finite volume based Cartesian grid method is adopted to solve the Reynolds averaged Navier-Stokes equations using a k-ε model for the turbulent closure and porous media model together. Numerical results reveal that waveform inversion weakens significantly, as the porosity of the obstacle increases, except when porosity nf<0.2. At the same time, the magnitude of vorticity and turbulent energy decrease remarkably due to acute reduction of the production term induced by percolation and wave-pore interaction. Moreover, a skewed hump shaped relation appears between the maximum vorticity and the porosity. For transmitted wave energy on a horizontal plateau, total energy may decrease as nf<0.2 but increases moderately while nf>0.2 during a strong wave-obstacle interaction.

AB - A permeable seabed may influence the evolution of an internal solitary wave propagating on a continental shelf and nearshore. In order to study the porous effect, numerical simulations are performed to investigate the flow field and waveform inversion of a large depression ISW propagating over a porous trapezoidal obstacle. A finite volume based Cartesian grid method is adopted to solve the Reynolds averaged Navier-Stokes equations using a k-ε model for the turbulent closure and porous media model together. Numerical results reveal that waveform inversion weakens significantly, as the porosity of the obstacle increases, except when porosity nf<0.2. At the same time, the magnitude of vorticity and turbulent energy decrease remarkably due to acute reduction of the production term induced by percolation and wave-pore interaction. Moreover, a skewed hump shaped relation appears between the maximum vorticity and the porosity. For transmitted wave energy on a horizontal plateau, total energy may decrease as nf<0.2 but increases moderately while nf>0.2 during a strong wave-obstacle interaction.

KW - Internal solitary wave

KW - k-ε turbulent model

KW - Permeable obstacle

KW - RANS equation

UR - http://www.scopus.com/inward/record.url?scp=85002538182&partnerID=8YFLogxK

U2 - 10.1016/j.oceaneng.2016.11.067

DO - 10.1016/j.oceaneng.2016.11.067

M3 - Article

AN - SCOPUS:85002538182

SN - 0029-8018

VL - 130

SP - 126

EP - 141

JO - Ocean Engineering

JF - Ocean Engineering

ER -

Effect of porosity on an internal solitary wave propagating over a porous trapezoidal obstacle

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