Computer algebra describes flow of turbulent floods via the Smagorinski large eddy closure

Abstract

[Abstract]: Consider the turbulent flow of a layer of fluid. The Smagorinski closure for turbulence, with its linear dependence of eddy viscosity upon the shear-rate, models turbulent dissipation. A slow manifold model of the dynamics of the fluid layer allows for large changes in layer thickness provided the changes occur over a large enough lateral length scale. The slow manifold is based on two macroscopic modes by modifying the spectrum: here artificially modify the boundary conditions on the free surface so that, as well as a mode representing conservation of fluid, a lateral shear flow with slip is a neutral critical mode. Then remove the modification to recover a model for turbulent floods.