Two-phase experimental and numerical studies on scouring at the toe of vertical seawall

This paper presents experimental and numerical modeling of scouring erosion at the toe due to wave impact on a highly reflective vertical seawall. For the experimental study, new experiments and analyses are provided in the light of advanced measurement techniques. They show the complex nature of the triple wave–structure–sediment interactions with their non-linearities, asymmetries, and hysteresis. For the numerical study, a two-dimensional x/z two-phase Eulerian model is introduced using a new fluid–solid particle interaction. The numerical model is also based on a projection technique, σ-transformation, and a second-order hybrid finite-difference and finite-volume method. A good agreement is obtained between the numerical and experimental results. Both models show that the wave run-up or down on vertical wall conducts to the formation of ascending or impinging vertical jets, which leads to the seawall scour.