Numerical Simulation of the Boundary Layer Flow Generated in Monterey Bay, California, by the 2010 Chilean Tsunami: Case Study

This work presents a case study involving the numerical simulation of the unsteady boundary layer generated by the 2010 Chilean tsunami, as measured by field equipment in Monterey Bay, California, USA. A one-dimensional vertical (1DV) boundary layer model is utilized, solving Reynolds-averaged Navier-Stokes equations, coupled with two-equation k-omega turbulence closure. Local effects of convective acceleration (converging-diverging effects) on the boundary layer due to the sloping bed are likewise approximated. Four cases are considered involving simulation of: (1) the long tsunami-induced boundary layer flow in isolation, in combination with either (2) convective acceleration effects or (3) energetic short wind waves, and, finally, (4) all effects combined. Reasonable agreement with field measurements is achieved, with model results similarly showing that the tsunami-induced boundary layer in this case only spans a fraction of the local water depth. Systematic comparison of the various cases likewise elucidates the likely significance of both local converging-diverging effects, as well as interaction with the much shorter period wind waves, on the tsunami-generated boundary layer. In the latter case, analogy is drawn to well-known wave-current boundary layer interaction, with the boundary layer turbulence associated with the short wind waves inducing an effective wave roughness felt by the tsunami-induced flow, which effectively plays the role of the current. (C) 2021 American Society of Civil Engineers.

Automated summary

This work presents a case study on the numerical simulation of the unsteady boundary layer generated by the 2010 Chilean tsunami in Monterey Bay, California, USA. The study utilizes a one-dimensional vertical boundary layer model, solving Reynolds-averaged Navier-Stokes equations and two-equation k-omega turbulence closure. It demonstrates that the tsunami-induced boundary layer only spans a fraction of the local water depth, and highlights the likely significance of local converging-diverging effects and interaction with short wind waves on the generated boundary layer.