In this paper the propagation and breaking of the solitary wave,the sinusoidal wave and the second Stokes wave on a slope of 1/30 are discussed based upon the TUMMAC method,and the velocity fields of breaking waves on...In this paper the propagation and breaking of the solitary wave,the sinusoidal wave and the second Stokes wave on a slope of 1/30 are discussed based upon the TUMMAC method,and the velocity fields of breaking waves on the slope are obtained by using the tracing method.The.numerical results for wave deformation are in good agreement with experimental data,and the breaker indexes depending on the kinetic criterion agree approximately with previ- ous results.Furthermore,compared with the experimental results measured by Iwagaki and by the authors,the tendency of velocity distribution of breaking waves computed by this numerical method is also satisfactory.展开更多
Using the slot method, the moving boundary problem caused by the change of the tide water elevation is treated. A two-dimensional advection - diffusion model with moving boundary is proposed, and the input pollutant i...Using the slot method, the moving boundary problem caused by the change of the tide water elevation is treated. A two-dimensional advection - diffusion model with moving boundary is proposed, and the input pollutant is considered as moving source to meet the water level variation. The model given in this paper has been used to simulate the pollutant transport in the Bohai Gulf, the computational results are in good agreement with the measured data.展开更多
Based on theoretical analysis, numerical calculation, and experimental study. this paper discusses breaker indices of irregular waves, transformation of wave spectrum, characteristics and computation of breaking waves...Based on theoretical analysis, numerical calculation, and experimental study. this paper discusses breaker indices of irregular waves, transformation of wave spectrum, characteristics and computation of breaking waves, as well as the critical beach slope under which waves will not break. Computed results are in good agreement with laboratory physical model test data and ocean wave field measurements.展开更多
Nelson pointed out that the wave breaking criterion( H/d)(b) for gentle slopes( i < 1/100), in which H is the wave height and d is the water depth at the breaking point, is smaller than that for beach slopes of i &...Nelson pointed out that the wave breaking criterion( H/d)(b) for gentle slopes( i < 1/100), in which H is the wave height and d is the water depth at the breaking point, is smaller than that for beach slopes of i > 1/100, i. e., the value oft H/d)(b) for gentle slopes may be smaller than 0.6. Goda indicated that the wave breaking criterion given by himself is a result based on theoretical study, so it should be also correct and can be used for gentle beaches, i.e., the value of(H/d)(b) for gentle slopes may be still larger than 0.7. By use of high order nonlinear wave theory, this problem is analyzed in this study and the reason why there is a large difference between different studies is explained. Moreover, the bottom energy loss during wave propagation is considered and the critical slope for the absence of wave breaking is also analyzed.展开更多
The tide induced groundwater fluctuation and the seawater intrusion have important effects on hydrogeology and ecology of coastal aquifers.Among previous studies,there were few quantitative evaluations of the joint ef...The tide induced groundwater fluctuation and the seawater intrusion have important effects on hydrogeology and ecology of coastal aquifers.Among previous studies,there were few quantitative evaluations of the joint effects of the beach slope and the tide fluctuation on the groundwater dynamics.In this article,a numerical model is built by using the software FEFLOW with consideration of seawater intrusion,tide effects,density dependent flow and beach sloping effects.The simulation results are validated by laboratory experimental data in literature.More numerical scenarios are designed in a practical scale with different beach slopes.Results show that the groundwater fluctuation decays exponentially with the distance to the beach,i.e.,,and our simulation further shows that the beach slope influence can be expressed in the form of a logarithm function.While for the same location,the amplitude increases logarithmically with the beach angle in the form,where and are related with the horizontal distance（）in the form of a logarithm function.The beach slope has no influence on the phase lag,although the latter increases regularly with the distance from the sea.The beach slope effect on the seawater intrusion is investigated through the quantitative relationship among the relative intrusion length（）,the relative enhancement of the tide induced seawater intrusion（）and the beach angle（）.It is shown that the tide effects on a milder beach is much greater than on a vertical one,and both λ and κ can be expressed in logarithm functions of.The tidal effect on the flow field in the transition zone for a particular mild beach is also studied,with results showing that the tide induced fluctuation of is similar to the groundwater table fluctuation while shows a distinct variation along both directions.展开更多
文摘In this paper the propagation and breaking of the solitary wave,the sinusoidal wave and the second Stokes wave on a slope of 1/30 are discussed based upon the TUMMAC method,and the velocity fields of breaking waves on the slope are obtained by using the tracing method.The.numerical results for wave deformation are in good agreement with experimental data,and the breaker indexes depending on the kinetic criterion agree approximately with previ- ous results.Furthermore,compared with the experimental results measured by Iwagaki and by the authors,the tendency of velocity distribution of breaking waves computed by this numerical method is also satisfactory.
文摘Using the slot method, the moving boundary problem caused by the change of the tide water elevation is treated. A two-dimensional advection - diffusion model with moving boundary is proposed, and the input pollutant is considered as moving source to meet the water level variation. The model given in this paper has been used to simulate the pollutant transport in the Bohai Gulf, the computational results are in good agreement with the measured data.
基金This project was supported financially by National Natural Science Foundation of China(No.49876026)Research Foundation for the Development of Engineering Technical Code of the Ministry of Communications
文摘Based on theoretical analysis, numerical calculation, and experimental study. this paper discusses breaker indices of irregular waves, transformation of wave spectrum, characteristics and computation of breaking waves, as well as the critical beach slope under which waves will not break. Computed results are in good agreement with laboratory physical model test data and ocean wave field measurements.
基金National Natural Science Foundation of China(Grant No.49876026)Foundation for Development of Engineering Technical Code of the Ministry of Communications of China
文摘Nelson pointed out that the wave breaking criterion( H/d)(b) for gentle slopes( i < 1/100), in which H is the wave height and d is the water depth at the breaking point, is smaller than that for beach slopes of i > 1/100, i. e., the value oft H/d)(b) for gentle slopes may be smaller than 0.6. Goda indicated that the wave breaking criterion given by himself is a result based on theoretical study, so it should be also correct and can be used for gentle beaches, i.e., the value of(H/d)(b) for gentle slopes may be still larger than 0.7. By use of high order nonlinear wave theory, this problem is analyzed in this study and the reason why there is a large difference between different studies is explained. Moreover, the bottom energy loss during wave propagation is considered and the critical slope for the absence of wave breaking is also analyzed.
基金supported by the Program for New Century Excellent Talents in Universities(Grant No.07-0814)
文摘The tide induced groundwater fluctuation and the seawater intrusion have important effects on hydrogeology and ecology of coastal aquifers.Among previous studies,there were few quantitative evaluations of the joint effects of the beach slope and the tide fluctuation on the groundwater dynamics.In this article,a numerical model is built by using the software FEFLOW with consideration of seawater intrusion,tide effects,density dependent flow and beach sloping effects.The simulation results are validated by laboratory experimental data in literature.More numerical scenarios are designed in a practical scale with different beach slopes.Results show that the groundwater fluctuation decays exponentially with the distance to the beach,i.e.,,and our simulation further shows that the beach slope influence can be expressed in the form of a logarithm function.While for the same location,the amplitude increases logarithmically with the beach angle in the form,where and are related with the horizontal distance（）in the form of a logarithm function.The beach slope has no influence on the phase lag,although the latter increases regularly with the distance from the sea.The beach slope effect on the seawater intrusion is investigated through the quantitative relationship among the relative intrusion length（）,the relative enhancement of the tide induced seawater intrusion（）and the beach angle（）.It is shown that the tide effects on a milder beach is much greater than on a vertical one,and both λ and κ can be expressed in logarithm functions of.The tidal effect on the flow field in the transition zone for a particular mild beach is also studied,with results showing that the tide induced fluctuation of is similar to the groundwater table fluctuation while shows a distinct variation along both directions.
