Vertical Grid Design for More Accurate and Efficient Surf Zone Simulation

Abstract

Nonuniform vertical discretization is investigated for use with a previously developed numerical model that solves the incompressible, nonhydrostatic, Navier–Stokes equations for free surface flow. The equations are vertically transformed to the sigma coordinate system and solved in a fractional step manner in which the pressure is computed implicitly by correcting the hydrostatic flow field to be divergence free. A specific discretization is proposed to attain greater accuracy and/or minimize computational effort when compared to a uniform vertical discretization. Numerical accuracy is assessed by comparison with experimental data for spilling and plunging breakers.