Comparison of finite element methods for the St. Venant equations
| Autor: | P. M. Steffler, F. E. Hicks |
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| Rok vydání: | 1995 |
| Předmět: |
Wave propagation
Applied Mathematics Mechanical Engineering Mathematical analysis Computational Mechanics Geometry Supercritical flow Least squares Finite element method Computer Science Applications Open-channel flow Physics::Fluid Dynamics symbols.namesake Mechanics of Materials Fourier analysis symbols Sensitivity (control systems) Diffusion (business) Mathematics |
| Zdroj: | International Journal for Numerical Methods in Fluids. 20:99-113 |
| ISSN: | 1097-0363 0271-2091 |
| DOI: | 10.1002/fld.1650200202 |
| Popis: | Finite element schemes for hyperbolic systems are applied to the St. Venant equations for one-dimensional, unsteady, open channel flow. The comparative performances of the characteristic-dissipative-Galerkin, Taylor-Galerkin and least squares finite element schemes are assessed by means of linear Fourier analysis and solution of idealized non-linear wave propagation problems. Of particular interest is the behaviour of these schemes for the regressive wave component in both subcritical and supercritical flows. To assess the quality of the basic solution, the methods are compared without any additional artificial diffusion or shock-capturing formulations. The balanced treatment of both wave components in the characteristic-dissipative-Galerkin method is illustrated. Also, the method displays little sensitivity to parameters variations. The Taylor-Galerkin scheme provides good solutions, although oscillations due to wave dispersion and minimal diffusion of the regressive wave are displayed. Also, this method is somewhat sensitive to the time step increment. The least squares method is considered unsuitable for unsteady, open channel flow problems owing to its inability to propagate a regressive wave in a supercritical flow. |
| Databáze: | OpenAIRE |
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