Multi-phase-fluid discrimination with local fibre-optical probes: I. Liquid/liquid flows
| Autor: | E. J. Fordham, S.-M. Huang, A. Holmes, C. P. Lenn, Rogerio Tadeu Ramos, S. Simonian |
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| Rok vydání: | 1999 |
| Předmět: | |
| Zdroj: | Measurement Science and Technology. 10:1329-1337 |
| ISSN: | 1361-6501 0957-0233 |
| DOI: | 10.1088/0957-0233/10/12/331 |
| Popis: | We demonstrate the use of a novel design of fibre-optical sensor (or `local probe') for immiscible-fluid discrimination in multi-phase flows. These probes are made from standard silica fibres with plane oblique facets polished at the fibre tip, with various surface treatments, including a crucial one for wettability control. Total internal reflection is used to distinguish drops, bubbles or other regions of fluid in multi-phase flows, on the basis of refractive-index contrast. Such probes have quasi-binary outputs; we demonstrate in this paper their use in distinguishing water from oil (kerosene) in oil/water two-phase flows and compare the results with those obtained from a simple cleaved fibre relying on the (small) difference in Fresnel reflectivity for discrimination. Quantitative accuracy is demonstrated by comparison of profiles, across a pipe diameter, of local, time-averaged volume fractions (`hold-ups'), with pipe-averaged hold-ups determined from a carefully calibrated gradio-manometer in a fully developed region of the flow. Companion papers deal with the sensors used and results achieved in gas/liquid flows and three-phase flows. |
| Databáze: | OpenAIRE |
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