Development of Large Scale Bed Forms in the Sea –2DH Numerical Modeling

Large repetitive patterns on the sea bed are commonly observed in sandy areas. The formation of the bed forms have been studied extensively in literature using linear stability analyses, commonly conducted analytically and with simplifications in the governing equations. This work presents a shallow water equation model that is used to numerically simulate the morphodynamics of the water-bed system.

The model includes separate formulations for bed load and suspended load, featuring bed load correction due to a sloping bed and modelled helical flow effects. Horizontal gradients are computed with spectral accuracy, which proves highly efficient for the analysis. Numerical linear stability analysis is used to identify the likely emergence of dominant finite sized bed forms, as a function of governing parameters.

These are then used for interpretation of the results of a long time morphological simulation.