CHARACTERISTICS OF TURBULENT BOUNDARY LAYER OVER A ROUGH BED UNDER CNOIDAL WAVES MOTION

Abstract

Ocean waves in reality often have a strong non-linear shape when propagating to shallow water, and the gap from the sinusoidal wave become remarkable. Therefore, it is generally believed that wave boundary layers, bottom shear stress and sediment transport behaviors actualizing the effect of non-linearity are different from sinusoidal wave. However, the example of research treating such turbulent boundary layer and sediment transport characteristic is very few. Therefore, the accuracy of bottom shear stress and amount of sediment transport used to evaluate the beach morphological change obtained from the wave motion model of sinusoidal is necessary to be clarified by that of non-linear. In this present study, turbulent boundary layer characteristics for asymmetric or non -linear waves according to the non-linearity effect is examined through both experimental and BSL turbulence model. Moreover, a new calculation method of botto m shear stress based on incorporating acceleration and velocity terms is used to examine both the experimental and BSL model results of bottom shear stress.