TY - JOUR
T1 - Numerical Study of the Effect of Submerged Vertical Breakwater Dimension on Wave Hydrodynamics and Vortex Generation
AU - Hajivalie, Fatemeh
AU - Yeganeh-Bakhtiary, Abbas
AU - Bricker, Jeremy D.
N1 - Publisher Copyright:
© 2015 World Scientific Publishing Company and Japan Society of Civil Engineers.
PY - 2015/9/19
Y1 - 2015/9/19
N2 - The effect of submerged vertical breakwater dimension on wave hydrodynamics and vortex generation around the breakwater is investigated with numerical modeling via two dimensionless parameters: the breakwater dimensionless submergence depth (a/Hi; a-the breakwater depth of submergence) and the Keulegan-Carpenter number (KC = Hiπ/Lbw; Hi-incident wave-height and Lbw-breakwater width). In the numerical model, Reynolds Averaged Navier-Stokes (RANS) equations with a standard k-ε turbulence closure model were implemented; the free surface was traced using the VOF method. A total of 10 different simulations with different KC number and breakwater submergence depth were conducted for this study. The results revealed that the transmission coefficient increases with increasing a/Hi and KC number, but that the effect of the KC number is not linear like the relation to a/Hi. For the waves modeled, the transmission coefficient increases dramatically with increasing the KC number until the KC number reaches a critical value, this critical value is observed when breakwater width is equal to a quarter of wavelength. This gives a hint in design of breakwater width. Turbulence intensity decreases with increasing a/Hi and KC on the seaside of the breakwater while it increases especially near the bed on the leeside of the breakwater; this can increase scour risk on the leeside of the breakwater. The optimum a/Hi for both, high-energy dissipation rate and low risk of scour tends to 3.5 for KC ≈ 1.0.
AB - The effect of submerged vertical breakwater dimension on wave hydrodynamics and vortex generation around the breakwater is investigated with numerical modeling via two dimensionless parameters: the breakwater dimensionless submergence depth (a/Hi; a-the breakwater depth of submergence) and the Keulegan-Carpenter number (KC = Hiπ/Lbw; Hi-incident wave-height and Lbw-breakwater width). In the numerical model, Reynolds Averaged Navier-Stokes (RANS) equations with a standard k-ε turbulence closure model were implemented; the free surface was traced using the VOF method. A total of 10 different simulations with different KC number and breakwater submergence depth were conducted for this study. The results revealed that the transmission coefficient increases with increasing a/Hi and KC number, but that the effect of the KC number is not linear like the relation to a/Hi. For the waves modeled, the transmission coefficient increases dramatically with increasing the KC number until the KC number reaches a critical value, this critical value is observed when breakwater width is equal to a quarter of wavelength. This gives a hint in design of breakwater width. Turbulence intensity decreases with increasing a/Hi and KC on the seaside of the breakwater while it increases especially near the bed on the leeside of the breakwater; this can increase scour risk on the leeside of the breakwater. The optimum a/Hi for both, high-energy dissipation rate and low risk of scour tends to 3.5 for KC ≈ 1.0.
KW - KC number
KW - RANS equations
KW - VOF method
KW - dimensionless submergence depth
KW - k-ε model
KW - transmission coefficient
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U2 - 10.1142/S0578563415500096
DO - 10.1142/S0578563415500096
M3 - Article
AN - SCOPUS:84941874772
VL - 57
JO - Coastal Engineering in Japan
JF - Coastal Engineering in Japan
SN - 0578-5634
IS - 3
M1 - 1550009
ER -