Bottom boundary layer

Figure 23.3 The processes which contribute to the exchange flux between open water (op) and sediment column (sc) (a) settling of suspended particles (b) exchange flux of dissolved phase across a stagnant bottom boundary layer, (c) particle resuspension followed by equilibration between particle and open water.

Eremeev VN, Ivanov LI, Samodurov AS, Duman M (1997) Bottom boundary layer in the Black Sea a simple model of formation. In Ozsoy E, Mikaelyan A (eds) Sensitivity to change Black Sea, Baltic Sea and Northern Sea. Kluwer, Dordrecht, p 275... 

Armi L. (1977) Dynamics of the bottom boundary layer of the deep ocean. In Bottom Turbulence, Proceedings of the 8th International liege Colloqium on Ocean Hydrodynamics (ed. J. C. J. Nihoul). Elsevier, New York, pp. 153—164. 

The particle velocity associated with the shallow water wave is elliptic ally with the major axis aligned parallel to the bottom and the minor axis perpendicular to it. The amplimde of the particle velocity decays with depth but remains finitely by close to the bottom where the minor axis of the particle motion approaches to zero. This implies that particle motions of shallow water waves are quite capable of resuspending sediments as well as to develop a turbulent bottom boundary layer. 

To simulate the transport of sedimentary material in the water column over realistic topography, it is necessary to run a three-dimensional circulation model, which is extended by submodels describing the surface waves, (Schwab et al., 1984), the shear forces within the bottom boundary layer, and the resulting deposition and erosion processes at the seabed. 

A similar process leads to the following solution for M in the bottom boundary layer ... 

Similar treatment can be done for the bottom boundary layer and we obtain v = 0 and... 

Figure 6 shows the distributions of the streaming velocity for three depths of the fluid layer with the parameter set presented previously. The magnitude of streaming velocity increases on the whole as the depth decreases. Further decrease of h results in the overlap of the top and bottom boundary layers, and so the analytical solutions presented so far may not hold in that case. 

For the horizontal velocity in the bottom boundary layer, Eqs. (155,173) yield... 

Note that as we do not need an explicit expression for the temperature field in the bottom boundary layer, the results do not depend on the type of heat exchange at the solid support. Finally, let us use BC (165) for the tangential stress balance. It becomes... 

See the books by Nielsen (Coastal Bottom Boundary Layers and Sediment Transport, World Scientific, 1992) and Fredsoe and Deigaard (Meehanics of Coastal Sediment Transport, World Scientific, 1992). 

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