Irregular wave bottom boundary layer over rough bed

An understanding of nature of the wave boundary layer above the seabed is of fundamental importance to coastal engineers and workers in the field of sediment transport. Waves in natural coastal environment are essentially irregular and the properties in the bottom boundary layer are different from those under purely sinusoidal waves. Therefore, it is appropriate to investigate boundary layer behavior over rough bed under irregular waves to achieve the most representative estimation of bottom shear stress in coastal sediment process. The bottom boundary layer in water wave propagation is important factor which influences the near shore morphodynamics and ecosystems in which bottom shear stress is responsible for sediment transport. In the present paper, the behaviors of the rough turbulent boundary layer for irregular wave has been investigated by the BSL k - ω turbulence model and validated by the available experimental data. The turbulence numerical models could predict well the mean velocity, turbulent intensity and time variation of bottom shear stress under irregular waves. This paper may be helpful in defining a suitable model for a specific practical application in coastal environments.