Non-linear diffusion equations with numerical stability problems are common in many branches of science. An example is the k-diffusion parametrization for vertical turbulent mixing in atmospheric models that creates a system of non-linear diffusion equations with stability problems. In this paper a
Asymptotically Stable Fourth-Order Accurate Schemes for the Diffusion Equation on Complex Shapes
โ Scribed by Saul Abarbanel; Adi Ditkowski
- Publisher
- Elsevier Science
- Year
- 1997
- Tongue
- English
- Weight
- 419 KB
- Volume
- 133
- Category
- Article
- ISSN
- 0021-9991
No coin nor oath required. For personal study only.
โฆ Synopsis
while constraining an energy norm of the error to be temporally bounded for all t ฯพ 0 by a constant proportional An algorithm which solves the multidimensional diffusion equation on complex shapes to fourth-order accuracy and is asymptoti-to the truncation error.
cally stable in time is presented. This bounded-error result is
In Section 3 it is shown how the methodology developed achieved by constructing, on a rectangular grid, a differentiation in Section 2 is used as a building block for the multidimenmatrix whose symmetric part is negative definite. The differentiation sional algorithm, even for irregular shapes containing matrix accounts for the Dirichlet boundary condition by imposing ''holes''.
penalty-like terms. Numerical examples in 2-D show that the method is effective even where standard schemes, stable by traditional Section 4 presents numerical results in two space dimendefinitions, fail. The ability of the paradigm to be applied to arbitrary sions illustrating the long-time temporal stability of the geometric domains is an important feature of the algorithm. แฎ 1997 method, in contradistinction to ''standard'' methods for a
Academic Press
Cartesian grid on irregular shapes.
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