Rheological Characterization of Fluids Using NMR Velocity Spectrum Measurements

This paper demonstrates the use of the nuclear magnetic resonance (NMR) velocity spectrum to rheologically characterize a fluid‐like material in steady tube flow. The velocity spectra for four different materials, an oil‐water solution, a polyacrylamide solution, tomato juice and a paper pulp suspension are measured and qualitative agreement with theory based upon simple constitutive models is demonstrated. These materials exhibit Newtonian, power law and Bingham plastic behavior. Homogeneous and heterogeneous samples are used and the applicability to each discussed. The velocity spectra from NMR experiments allows for a nonin‐vasive method of monitoring flow behavior and as such has applications to online process monitoring of rheological properties.