Numerical Investigation of Wave Reflection from a Stepped Breakwater

Yin, Z.; Jin, L.; Liang, B., and Wang, Y., 2017. Numerical investigation of wave reflection from a stepped breakwater.On the basis of a combination of the Reynolds-averaged Navier–Stokes equations, standard k-ϵ equations, and volume-of-fluid technique, a two-dimensional mathematical model was used to investigate the wave reflection performance of a stepped breakwater. A series of experiments was conducted to measure the wave heights and validate the mathematical model, and they exhibited good agreement. The aforementioned mathematical model was used to compute composite wave heights for different still-water depths, incident wave heights, wave periods, single step widths, and stepped breakwater slope scenarios. The two-probes method was used to determine the incident and reflected waves from the records of composite waves. The results showed that the stepped breakwater slope (especially for the gentle scenarios) plays a dominant role in wave reflection, and the wave reflection coefficient increases with increasing slope. However, it decreases with the increase of relative width of a single step and incident wave steepness respectively. Using the Iribarren number and the relative width of a single step, a simple formula for wave reflection coefficient was developed on the basis of the dimensional analysis method. It was validated using the corresponding data.