A two-dimensional experimental-numerical approach to investigate wave transformation over muddy beds

The effect of a thin fluid mud layer on nearshore two-dimensional wave transformation is studied through numerical modeling and wave basin experiments. The wave basin experiments were conducted on both muddy and fixed beds. A mixture of commercial kaolinite and tap water was used as fluid mud layer, where its rheological viscoelastic parameters were derived from rheometer cyclic tests. The results can be utilized for better understanding of the complex wave transformation phenomena under real field conditions where the combined effects of shoaling, refraction, and diffraction as well as wave energy dissipation due to existing mud beds and wave breaking jointly occur. A dissipation model was coupled to the combined refraction and diffraction 1 (REF/DIF 1) wave model to develop a numerical wave height transformation model for muddy beaches. The proposed model was utilized to analyze the experimental data on muddy beds. Comparing the computed values of wave heights over mud layer with the corresponding measurements shows a fair agreement.