Abstract
The swash zone is the most dynamic region in coastal areas as it is affected by different kinds of incident waves developing wave-swash interactions, which act as the principal precursor for sediment transport and liquefaction in this zone, whose behavior and link to the wave-swash interactions is often difficult to predict and quantify. Under controlled experiments performed in a wave flume, we replicate and develop a quantitative characterization of wave-swash interactions commonly observed in the field. Several wave amplitudes and separation times between two successive solitary wave events were combined to generate different types of interactions. We record the main features of these coastal phenomena using a camera and a set of co-located instruments to measure surface elevation, velocities, and bottom pressures. The experiments reveal the importance of considering the relation between the successive wave heights, namely the wave height ratio H2/H1, and the dimensionless temporal ratio defined as Tsep/Tswash, representing the arrival of the second wave event to the swash. For cases where the wave height ratio is close to the unity, interactions become less dependent on the separation time between the events, while when the consecutive waves have the same wave amplitude, the temporal ratio is enough to represent the interactions. Our investigations also show that interactions occur at different locations depending on the type of interaction. From the measurements collected at the interaction point in the swash, using the bottom pressures and water surface elevation information, we estimate interaction-induced upward-directed accelerations with an analytical approach based on the vertical component of the Navier-Stokes equation. The formulation associates the hydrostatic and non-hydrostatic pressures with the total vertical accelerations exerted by the interactions. These results show that wave-swash interactions could generate significant magnitudes for acceleration at the interaction point. We relate these findings to the development of local liquefaction, which might act as the starting process for the different sediment transport mechanisms on the coast.
About the Speaker
Claudio Meza-Valle is a PhD candidate at the University of Wisconsin-Madison, working under the supervision of Professor Nimish Pujara. He received an MSc in Applied Mathematics from the University of Chile and a BSc in Ocean Engineering from the University of Valparaíso in Chile. Before starting his journey as a doctoral student, Claudio was involved in the coastal engineering industry for seven years, where he had the chance to work on different projects in Chile and overseas. He specialized mainly in the numerical modeling of ocean and coastal processes, performing mathematical simulations of operational and extreme water wave events, wave hydrodynamics, sediment transport, and dynamic mooring analysis of ships for port operations.
Host: Professor Leonardo Chamorro
