Influence of the Weißenberg number on the stability of Oldroyd kind fluids
| Autor: | N. Scurtu, E. Bänsch |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
Renewable Energy
Sustainability and the Environment business.industry General Chemical Engineering Thermodynamics Computational fluid dynamics Type (model theory) System of linear equations Stability (probability) Non-Newtonian fluid Complement (complexity) Nonlinear system Applied mathematics Limit (mathematics) business Waste Management and Disposal Mathematics |
| Zdroj: | Asia-Pacific Journal of Chemical Engineering. 5:657-673 |
| ISSN: | 1932-2135 |
| DOI: | 10.1002/apj.384 |
| Popis: | This paper is concerned with nonlinear rheological fluids of Oldroyd type. We present a (formal) stability analysis of the corresponding system of equations, showing stability limits on the Weisenberg number in certain cases. To this end, we proceed in several steps, thus separating the possible sources for instabilities. First, a spectral analysis of the linearized Oldroyd system is presented. Then, the influence of the βa-term on the stability of the constitutive stress equation and of the full Oldroyd system is examined. Moreover, because this stability analysis is of formal and linear nature, we complement it by numerical simulations for the system showing that the upper limit of the Weisenberg number found by the stability analysis is fairly sharp. We thereby try to shed some light on the high Weisenberg number problem, that is, the problem why in certain cases there seem to exist no solutions to the Oldroyd problem for large Weisenberg numbers. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text