A method for the specification and design of finite difference spatial derivative approximations of general order r is presented. The method uses a difference polynomial with undetermined coefficients. Spatial frequency domain-based criteria, which include phase velocity, group velocity, and dissipa
A frequency accurate spatial derivative finite difference approximation
β Scribed by Peter A. Orlin; A. Louise Perkins; George Heburn
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 163 KB
- Volume
- 13
- Category
- Article
- ISSN
- 0749-159X
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β¦ Synopsis
We present a method for designing spatial derivative approximations that achieves a priori accuracy in the spatial frequency domain. We use a general, average value approximation with undetermined coefficients together with a set of constraints that ensure convergence and consistency to formulate a constrained optimal fitting problem. These constraints lead to a linear matrix formulation. We apply the method to the design of spatial approximations for simulating equations with wavelike solutions using both an explicit central difference approximation (which has no phase error) and an upwind design where the level of dissipation can be specified by the designer.
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