- Le Maitre, O. and Levin, J. and Iskandarani, M. and Knio, O. M., A multiscale pressure splitting of the shallow-water equations - I. Formulation and 1D tests,
JOURNAL OF COMPUTATIONAL PHYSICS, vol. 166 no. 1
pp. 116--151 .
(last updated on 2011/07/05)
Direct representation of the free surface in ocean circulation models leads to a number of computational difficulties that are due to the fast time scales associated with free-surface waves. These fast time scales generally result in severe time-step restrictions when the free surface is advanced using an explicit scheme and map result in large phase errors when the foe surface is treated implicitly with a large time step. A multiple-scale analysis of the shallow-water equations is used to analyze this stiffness and to guide the construction of a computational methodology that overcomes the associated difficulties. Specifically, we explore a class of fractional step methods that utilize coarsened grids in the propagation of long-wave data. The behavior of the corresponding schemes is examined in detail in light of one-dimensional model problems, based on finite-difference or spectral-element discretizations. (C) 2001 Academic Press.