CFD modeling of nonlinear tsunami wave run-up dynamics: Analytical calibration and estimation methods

This study delves into the intricate dynamics of tsunami wave run-up, with a specific focus on nonlinear wave behavior. Leveraging the self-manipulated interFoam solver, we scrutinized various factors influencing run-up, including surf-similarity, wave non-linearity and beach slope. The variation in run-up height with surf-similarity follows a consistent pattern for waves of different non-linearity: an initial increase followed by a decrease as surf-similarity intensifies. Low surf-similarity waves tend to exhibit intensive run-up with wave breaking, while high surf-similarity waves display gentler and prolonged run-up and run-down processes. Under fixed surf-similarity, tsunamis on mild slopes break more easily, yielding lower run-up heights compared to steep slopes. Furthermore, waves with higher non-linearity are more prone to breaking compared to waves with similar surf-similarity but lower non-linearity. We calibrate Madsen & Schäffer (2010)’s analytical solution and introduce semi-empirical methods for conservative estimation of run-up height and velocity, along with an empirical formula for estimating swash periods. This approach utilizes wave data along a sloping beach, eliminating the need for arbitrary input from the beach’s toe or offshore areas. Notably, our methods demonstrate feasibility on run-up height estimation for waves with non-linearity up to 1.3, indicating its applicability across a wide range of conditions. Despite inherent limitations, the proposed methods and formula signify potential additions to the toolkit for tsunami forecasts and hazard assessment, providing insights and alternative avenues for further exploration in this intricate field. •A systematic exploration of tsunami waves covering a broad range of surf-similarity, wave non-linearity and slope.•A self-manipulated interFoam solver to generate strongly nonlinear waves.•Under fixed surf-similarity, the beach slope significantly impacts wave run-up.•Empirical methods are proposed for estimations of run-up height, velocity and swash period.•The methods allow applying wave data at various locations along a sloping beach.