Flow of yield stress materials through annular abrupt expansion–contractions
| Autor: | C. R. de Miranda, Mônica F. Naccache, P. R. de Souza Mendes, Priscilla R. Varges, B. S. Fonseca |
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| Rok vydání: | 2020 |
| Předmět: |
Fluid Flow and Transfer Processes
Physics Yield (engineering) Mechanical Engineering media_common.quotation_subject Flow (psychology) Computational Mechanics Particle displacement Mechanics Flow pattern Condensed Matter Physics Laser 01 natural sciences 010305 fluids & plasmas law.invention Physics::Fluid Dynamics Cross section (physics) Mechanics of Materials law TRACER 0103 physical sciences Eccentricity (behavior) 010306 general physics media_common |
| Zdroj: | Physics of Fluids. 32:083101 |
| ISSN: | 1089-7666 1070-6631 |
| DOI: | 10.1063/5.0015400 |
| Popis: | We present an experimental study of the flow of yield stress materials through annular abrupt expansions–contractions, to evaluate the flow invasion into the cavity formed in the larger cross section region. Steady inertialess flows of Carbopol® aqueous dispersions were investigated. The flow pattern reveals yielded and unyielded regions, which were visualized using tracer particles, laser sheets, and a digital camera. The yield surfaces were identified in the experiments by choosing large enough exposure times that allow sufficient particle displacement in the yielded region. To estimate the amount of fluid that remains stagnant in the cavity, we defined the invasion ratio, a quantity that was determined through image processing for different combinations of the governing parameters. The influence of the cavity diameter and axial length, eccentricity, and inlet velocity on the invasion ratio was investigated. Fore-aft asymmetric yield surfaces were observed for all tests, probably due to elastic effects. |
| Databáze: | OpenAIRE |
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