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Updated: Jun 15, 2026
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In Situ Monitoring of Diffusion of Guest Molecules in Porous Media Using Electron Paramagnetic Resonance Imaging
Published on: September 2, 2016
Measurement of vorticity diffusion by NMR microscopy
Jennifer R Brown1, Paul T Callaghan
1Victoria University of Wellington, School of Chemical and Physical Sciences, The MacDiarmid Institute of Advanced Materials and Nanotechnology, PO Box 600, Wellington 6012, New Zealand. jbrown@coe.montana.edu
Journal of Magnetic Resonance (San Diego, Calif. : 1997)
|March 2, 2010
Summary
Researchers measured kinematic viscosity in low-viscosity fluids by imaging vorticity diffusion using rapid Nuclear Magnetic Resonance (NMR) velocimetry. This technique avoids direct stress measurements, offering a novel approach for fluid characterization.
Area of Science:
- Fluid dynamics
- Rheology
- Nuclear Magnetic Resonance (NMR) spectroscopy
Background:
- Vorticity diffusion in Newtonian fluids is governed by kinematic viscosity.
- Accurate measurement of kinematic viscosity is crucial for understanding fluid behavior.
- Traditional methods for viscosity measurement can be complex or require stress measurement.
Purpose of the Study:
- To develop and validate a novel method for measuring kinematic viscosity.
- To investigate the diffusion of vorticity in a fluid-filled cylinder during startup.
- To demonstrate the utility of rapid NMR velocimetry for fluid property determination.
Main Methods:
- Utilized rapid Nuclear Magnetic Resonance (NMR) velocimetry, employing a RARE sequence.
- Imaged the time-dependent velocity field within a fluid-filled cylinder.
- Initiated fluid motion by rotating the cylinder's outer wall to a fixed angular velocity.
Main Results:
- Successfully imaged the diffusion of vorticity.
- Experimental results align with the theoretical solution of the vorticity diffusion equation.
- Demonstrated a method to determine kinematic viscosity without direct stress measurement.
Conclusions:
- Rapid NMR velocimetry provides an effective means to measure kinematic viscosity.
- The technique is particularly suitable for low-viscosity fluids.
- This study offers a non-invasive approach for fluid characterization.
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