• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.6
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• pp.1037-1048
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• 2016

In this study, nonlinear wave interaction in the presence of a uniform current is studied using numerical model, named CADMAS-SURF which is based on the Navier-Stokes equations coupled with Volume of Fluid for tracking free surface deformation. The original CADMAS-SURF developed for interaction of wave with structure is modified/extended to simulate nonlinear fluid dynamic motions within wave-current coexisting field. The capability of Numerical Wave-Current Tank (NWCT) in this study is validated by comparing with available existing laboratory experiments for both wave-following and wave-opposing current. The numerical results for interaction between wave and current are shown to be in good agreement with experimental data. Then, this study focused on the dynamic motions of the water velocity, surface elevation and vorticity within combined wave-current field in demonstrating complex nonlinear physical phenomena due to interaction between wave and current. In addition, NWCT is applied to simulate a more complex wave-current-structure field for wave propagating over a submerged breakwater associated with current. Detailed discussion including characteristics of velocity and vorticity fields and the relation between free surface and vorticity are given.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2003.05a
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• pp.128-134
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• 2003

Numerical study on interactions of waves and currents has considerable practical interests in coastal and ocean engineering. And wave-current interactions strongly influence wave characteristics, current profiles, and forces on offshore structures. Presence of currents affects wave properties such as wave height and wave profiles. Furthermore, in case of the irregular waves, it is more complicated problem. The propose of present study, using the one-dimensional wave-current numerical model is based on the extended Boussinesq equation(Madsen, 1991) and an alternative form of wave-current dispersion relation(Mohiuddin, 1999, 2000) including wave action concept, is to simulate wave propagation in a current field including the irregular waves and discuss applicability of the model in a wave-current field.

• Journal of Ocean Engineering and Technology
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• v.12 no.3 s.29
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• pp.75-85
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• 1998

A finite difference model for predicting time-dependent, wave-induced nearshore current is studied. The model includes wave refraction, wave-current interaction, bottom friction and wind effect. This model iteratively solved the linear the linear set of conservation of both mass and momentum, which were time averaged (over one wave period) and depth integrated, for mean velocities and free surface displacement. Numerical simulations of nearshore current under oblique wave attack, and for wave and wind induced current on a longshore periodic beach are carried out. Longshore velocities tend to zero in some distances outside the breaker line. And the peak velocity is shifted shoreward at the breaker line. The results represent the general characteristics of the nearshore current induced by wave.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.675-678
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• 2008

The effect of wave and current interactions on jet-like current flowing against waves was investigated based on numerical simulations. The numerical simulations are conducted by a combined model system of REF/DIF(a wave model) plus SHORECIRC(a current model) and a Boussinesq equation model, FUNWAVE. In the simulations, regular and irregular waves refracted due to the jet-like opposing current were focused along the core region of current, and the jet-like current was earlier spreaded when the waves had larger wave heights. The numerical results show that the rapid change of wave height distribution in transverse direction near current inlet plays a significant role to spread the jet-like current. In other words, the gradients of radiation stress forcing in transverse direction have a more significant effect on the jet-like current than its relatively small gradients forcing in flowing direction, which tend to accelerate the current, do. In conclusion, it is indispensible to take into account the interaction effect of wave transformation and current characteristics when waves meet the opposing jet-like current such as river mouth.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2000.04a
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• pp.75-81
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• 2000

Water waves propagate over irregular bottom bathymetry are transformed by refraction, diffraction, shoaling, reflection etc. Principal factor of wave transform is bottom bathymetry, but in case of current field, current is another important factor which effect wave transformation. The governing equation of this study is develop as wave-current equation type to investigate the effect of wave-current interaction. This wave-current model was applied to the Kwangan beach which is located at Pusan. The numerical simulation results of this model show the characteristics of wave transformation and flow pattern around the Kwangan beach fairly well.

• Journal of Ocean Engineering and Technology
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• v.15 no.2
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• pp.6-10
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• 2001

Water waves propagate over irregular bottom bathymetry are transformed by refraction, diffraction, shoaling, reflection etc. Principal factor of wave transform is bottom bathymetry, but in case of current field, current is another important factor which effect wave transformation. The governing equation of this study is develope as wave-current equation type to investigate the effect of wave-current interaction. It starts from Berkhoff's(1972) mild slope equation and is transformed to time-dependent hyperbolic type equation by using variational principal. Finally the governing equation is shown as a parabolic type equation by splitting method. This wave-current model was applied to the kwangan beach which is located at Pusan. The numerical simulation results of this model show the characteristics of wave transformation and flow pattern around the Kwangan beach fairly well.

• Ocean and Polar Research
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• v.31 no.4
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• pp.389-399
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• 2009

Subsurface pressure gauge has many advantages in measuring a wide range of wave spectra in coastal waters from wind waves to long waves. However, a shortcoming of the gauge is related to the difficulties in recovering surface wave spectra from subsurface pressure records. In this study, the effect of current on the pressure transfer function of the pressure gauge, and hence on the surface wave energy spectrum, was investigated by analyzing the subsurface pressure data based on the linear wave theory. For this purpose, laboratory experiments were carried out in a wave-current flume. Subsurface pressure records, as well as the surface elevation data, were obtained simultaneously under different wave and current conditions. Pressure transfer functions were obtained and compared with those estimated from the linear wave theory, both with and without inclusion of the current-effect. It was established that wave spectra obtained from subsurface pressure gauge were in closer agreement with those from surface wave gauge when current-effect on the pressure transfer function was taken into consideration for analysis.

• Journal of Ocean Engineering and Technology
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• v.31 no.1
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• pp.36-46
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• 2017

Most of the studies on the hydraulic characteristics of wave-current interaction have used 2-D hydraulic experiments or 2-D numerical simulations. However, it is difficult to understand the wave-current interaction found in actual estuaries using these. Therefore, a numerical water tank was constructed in this study to perform simulations involving a 3-D river mouth. The result showed a change in the water surface at the river mouth from the wave-current interaction. With an increase in the ratio ($V_c/C_i$) between the river current and wave celerity, the wave height and mean water level of the river increased at the wave and current meeting point. A higher $V_c/C_i$ caused a stronger wave-current interaction and increased the turbulence kinetic energy. Thus, the wave height attenuation became larger by the wave-current interaction with a higher $V_c/C_i$. In addition, it was possible to understand the flow characteristics in the vicinity of the river mouth as a result of the wave-current interaction using the mean flow and mean time-averaged velocity at the mid-cross section of river.

• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.2
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• pp.185-193
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• 2010

In the present study, wave deformation and wave-induced current were calculated under the regular wave conditions using the Boussinesq model. The model results of the wave deformation showed good agreements with the preceeding laboratory experiments of others. The wave-induced current of the fully developed sea state was calculated. For field application of model, the preceeding field data by others in the real scale of the water area were compared, the numerical result of wave deformation showed a relatively good agreement with the field data. Although the numerical result of wave-induced current was underestimated over the longshore bar developed area, the Boussinesq model is generally suitable to predict the wave-induced current.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.3 no.2
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• pp.65-71
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• 1991

Many investigations of wave deformation without currents have been carried out experimentally and theoretically but, studies treating the effect of longshore current on the wave deformation are few. It is thus necessary to evaluate the effect of longshore current on the wave deformation after breaking. In the paper the wave height attenuation. the wave direction and the variation of mean water level are calculated in which effects of longshore current are involved. To assess the effect of longshore current on the wave deformation, factors above with longshore current are compared with them without longshore current by using calculated results.