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Process-based approach on tidal inlet evolution – Part 1
Published in C. Marjolein Dohmen-Janssen, Suzanne J.M.H. Hulscher, River, Coastal and Estuarine Morphodynamics: RCEM 2007, 2019
D.M.P.K. Dissanayake, J.A. Roelvink
The other variables are defined as follow. D is the total mean depth D=zs-zb.S‾' is the wave radiation stress tensor. S‾-'' is the turbulent Reynolds stress tensor. τb→ is the bed shear stress vector. g is the acceleration due to gravity. ρ the water density. cg→ is the group velocity vector. ε is the dissipation rate due to wave breaking and bottom friction. k → is the wave vector. q → is the horizontal sediment flux vector, determined by the Soulsby and Van Rijn formula (Soulsby 1997; Garnier et al. 2006). More details on the parameterization are given in Garnier et al. (2006).
Study on sediment transport of silt coast by wave and tidal current
Published in Silke Wieprecht, Stefan Haun, Karolin Weber, Markus Noack, Kristina Terheiden, River Sedimentation, 2016
Where: h is water depth (m); u, v are velocity in x, y direction (m/s); g is gravitation acceleration (m/s2); z0 is bed level (m); Cz is Chezy coefficient (m1/2/s); f is Coriolis parameter (s-1); Wx, Wy are wind stress (N/m2); vt is turbulent viscosity coefficient (m2/s); p is water density(kg/m3), is wave friction factor. Cz, Sxy, Syx, Syy are wave radiation stress′iN/m). The expressions for the 4 components of the wave radiation stress tensor are: Sxx=E[(2n−1/2)−nsin2θ]Sxy=Syx=Ensinθcosθ;Syy=E[(n−1/2)+nsin2θ].
Wave theory
Published in Dominic Reeve, Andrew Chadwick, Christopher Fleming, Coastal Engineering, 2018
Dominic Reeve, Andrew Chadwick, Christopher Fleming
Second, the radiation stress (Sxy) which constitutes the flux of y momentum parallel to the shoreline across a plane x = constant is given by Sxy=SXXsinαcosα−SYYsinαcosα=E(12+khsinh2kh)cosαsinα=E(cgc)cosαsinα.
Influence of the permeability of submerged breakwaters on surrounding wave and current fields
Published in Coastal Engineering Journal, 2023
Dilan Rathnayaka, Yoshimitsu Tajima
Phase-averaged volume flux over the breakwater should be determined by the balance of (i) wave-induced radiation stress force; (ii) friction force over the breakwater crest; and (iii) hydrostatic pressure gradient force due to wave setup. The shoreward wave-induced radiation stress force is highly dependent on breaking wave attenuation on the submerged breakwater. Estimation error of breaking wave dissipation by the present model computation can be the reason for the overestimation of the shoreward volume flux over the submerged breakwater. In the case of impermeable submerged breakwater, however, the computed wave height was slightly overestimated just behind the submerged breakwater, i.e. the model slightly underestimated the breaking wave attenuation. Since this slight underestimation of wave attenuation should lead to underestimation of the shoreward wave radiation stress force, it cannot explain the overestimation of the shoreward volume flux over the submerged breakwater. It should also be noted that there was little difference in computed wave attenuation rates between permeable and impermeable submerged breakwaters, indicating little difference in the wave radiation stress force between permeable and impermeable breakwaters.
Tidal inlet morphodynamics through numerical prediction and measurements
Published in Marine Georesources & Geotechnology, 2022
Vallam Sundar, Kantharaj Murali, Sukanya Ramesh Babu, A. Arun Rajasekar
The numerical model adapted for the study was developed over the years by Chitra, Murali, and Mahadevan (1996), and Murali, Sundar, and Sannasiraj (2014), where the local hydrodynamics are modelled and calibrated with the aid of field measured data. A vertically integrated form of shallow water equations (SWE) discretized by the finite volume method (FVM) is employed to mimic the real-field conditions in the model. The tide-induced current velocities can be obtained by solving the SWE (Eq. (1)), in the Cartesian coordinate system, where the z-axis represents the water depth. where η is the free surface elevation, u and v are the mean velocity vector components, h is the total depth (h = d + η) with d being the still water level. ε is the eddy viscosity, τwi surface stresses, τbi bed friction stresses (i = x, y), and f is the Coriolis parameter. Sij are the components of the radiation stress tensor that represent the excess momentum fluxes associated with the oscillatory wave motion.
Hydrodynamical and morphological patterns of a sandy coast with a beach nourishment suffering from a storm surge
Published in Coastal Engineering Journal, 2022
Xuejian Han, Cuiping Kuang, Lei Zhu, Lixin Gong, Xin Cong
The wave-current interaction is implemented through the two-way coupling of the Delft3D-FLOW and Delft3D-WAVE module using a so-called communication file that carries the necessary information for these two modules. The data transfer between these two modules is operated as follows: firstly, the Delft3D-FLOW module yields the flow output, and the water level and current velocity are store in the communication file. Then the Delft3D-WAVE module incorporates these two parameters into the wave computation and stores the wave characteristics (wave height, wave direction, and mass fluxes) into the communication file. Next the current-affected wave parameters are taken into count in the flow computation through several aspects: the enhanced vertical mixing due to waves, the wave-induced net mass flux, the wave-induced momentum flux (radiation stress), and the enhanced bed shear stress due to waves. At this point a two-way coupling round is finished.