Validation of a low field Rheo-NMR instrument and application to shear-induced migration of suspended non-colloidal particles in Couette flow
| Autor: | R Barua, Lynn F. Gladden, Sean Lovett, John C. Mitchell, Andrew J. Sederman, Thomas W. Blythe, Adam A. Colbourne |
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| Přispěvatelé: | Sederman, Andy [0000-0002-7866-5550], Gladden, Lynn [0000-0001-9519-0406], Apollo - University of Cambridge Repository |
| Rok vydání: | 2018 |
| Předmět: |
Nuclear and High Energy Physics
Materials science Field (physics) Biophysics Analytical chemistry Rheo-NMR 01 natural sciences Biochemistry 010305 fluids & plasmas Rheology 0103 physical sciences Newtonian fluid Shear stress Couette flow Particle migration 010304 chemical physics Mechanics Condensed Matter Physics Condensed Matter::Soft Condensed Matter Shear (sheet metal) Low field Magnet Process monitoring Particle Non-colloidal particles |
| Zdroj: | Journal of Magnetic Resonance. 286:30-35 |
| ISSN: | 1090-7807 |
| DOI: | 10.1016/j.jmr.2017.11.010 |
| Popis: | Nuclear magnetic resonance rheology (Rheo-NMR) is a valuable tool for studying the transport of suspended non-colloidal particles, important in many commercial processes. The Rheo-NMR imaging technique directly and quantitatively measures fluid displacement as a function of radial position. However, the high field magnets typically used in these experiments are unsuitable for the industrial environment and significantly hinder the measurement of shear stress. We introduce a low field Rheo-NMR instrument ( 1 H resonance frequency of 10.7 MHz ), which is portable and suitable as a process monitoring tool. This system is applied to the measurement of steady-state velocity profiles of a Newtonian carrier fluid suspending neutrally-buoyant non-colloidal particles at a range of concentrations. The large particle size (diameter > 200 μ m ) in the system studied requires a wide-gap Couette geometry and the local rheology was expected to be controlled by shear-induced particle migration. The low-field results are validated against high field Rheo-NMR measurements of consistent samples at matched shear rates. Additionally, it is demonstrated that existing models for particle migration fail to adequately describe the solid volume fractions measured in these systems, highlighting the need for improvement. The low field implementation of Rheo-NMR is complementary to shear stress rheology, such that the two techniques could be combined in a single instrument. |
| Databáze: | OpenAIRE |
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