Studies of barotropic flow over topography using a Galerkin Finite Element model
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Authors
Petroliagis, Thomas I.
Subjects
Advisors
Williams, Roger Terry
Date of Issue
1988
Date
Publisher
Monterey, California. Naval Postgraduate School
Language
en_US
Abstract
A finite element shallow-water model is tested with two types of surface topography. The model uses rectangular subdivisions in a vorticity-divergence formulation, and a semi-implicit time discretization. In the first experiment an east-west ridge or valley is placed in a channel with east-west periodic conditions. Linear quasi-geostrophic solutions are derived with the rigid lid assumption. The Rossby waves are successfully simulated in the model with linear solutions as the initial conditions. The model phase speeds are very close to the analytic values when the latter are properly corrected. In the second experiment a ridge is placed across the channel and the Coriolis parameter is set to zero. The initial conditions consist of a uniform flow through the channel and constant free-surface height. The numerical simulations agree with hydraulic jump theory. In the jump cases the model predicts increasing wind speeds and decreasing free surface heights. Higher spatial resolution would be required to properly simulate the details of the hydraulic jump formation. (fr)
Type
Thesis