A reformed numerical model based on the 'one-line theory' for beach deformation is presented. In this model, the change of beach slope during coastline procession is considered.A wave numerical model combined ...A reformed numerical model based on the 'one-line theory' for beach deformation is presented. In this model, the change of beach slope during coastline procession is considered.A wave numerical model combined with wave refraction, diffraction and reflection is used to simulate wave climate to increase numerical accuracy.The results show that the numerical model has a good precision based on the adequate field data. The results can be applied to practical engineering.展开更多
Time-averaged suspended sediment concentration profiles across the surf zone were measured in a large-scale three-dimensional movable bed laboratory facility (LSTF:Large-scale Sediment Transport Facility). Sediment su...Time-averaged suspended sediment concentration profiles across the surf zone were measured in a large-scale three-dimensional movable bed laboratory facility (LSTF:Large-scale Sediment Transport Facility). Sediment suspension under two different types of breaking waves, spilling and plunging breakers, was investigated. The magnitudes and shapes of the concentration profiles varied substantially at different locations across the surf zone, reflecting the different intensities of breaking-induced turbulence. Sediment sus- pension at the energetic plunging breaker-line was much more active, resulting in nearly homogeneous concentration profiles throughout most of the water column, as compared to the reminder of the surf zone and at the spilling breaker-line. Four suspended sediment concentration models were examined based on the LSTF data, including the mixing turbulence length approach, segment eddy viscosity model, breaking-induced wave-energy dissipation approach, and a combined breaking and turbulence length model developed by this study. Neglecting the breaking-induced turbulence and subsequent sediment mixing, suspended sediment concentration models failed to predict the across-shore variations of the sediment suspension, especially at the plunging breaker-line. Wave-energy dissipation rate provided an accurate method for estimating the intensity of turbulence generated by wave breaking. By incorporating the breaking-induced turbulence, the combined breaking and turbulence length model reproduced the across-shore variation of sediment suspension in the surf zone. The combined model reproduced the measured time-averaged suspended sediment concentration profiles reasonably well across the surf zone.展开更多
文摘A reformed numerical model based on the 'one-line theory' for beach deformation is presented. In this model, the change of beach slope during coastline procession is considered.A wave numerical model combined with wave refraction, diffraction and reflection is used to simulate wave climate to increase numerical accuracy.The results show that the numerical model has a good precision based on the adequate field data. The results can be applied to practical engineering.
基金funded by the U.S.Army Engineer Research and Development Center and the Louisiana Sea Grant College Program
文摘Time-averaged suspended sediment concentration profiles across the surf zone were measured in a large-scale three-dimensional movable bed laboratory facility (LSTF:Large-scale Sediment Transport Facility). Sediment suspension under two different types of breaking waves, spilling and plunging breakers, was investigated. The magnitudes and shapes of the concentration profiles varied substantially at different locations across the surf zone, reflecting the different intensities of breaking-induced turbulence. Sediment sus- pension at the energetic plunging breaker-line was much more active, resulting in nearly homogeneous concentration profiles throughout most of the water column, as compared to the reminder of the surf zone and at the spilling breaker-line. Four suspended sediment concentration models were examined based on the LSTF data, including the mixing turbulence length approach, segment eddy viscosity model, breaking-induced wave-energy dissipation approach, and a combined breaking and turbulence length model developed by this study. Neglecting the breaking-induced turbulence and subsequent sediment mixing, suspended sediment concentration models failed to predict the across-shore variations of the sediment suspension, especially at the plunging breaker-line. Wave-energy dissipation rate provided an accurate method for estimating the intensity of turbulence generated by wave breaking. By incorporating the breaking-induced turbulence, the combined breaking and turbulence length model reproduced the across-shore variation of sediment suspension in the surf zone. The combined model reproduced the measured time-averaged suspended sediment concentration profiles reasonably well across the surf zone.
