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Tomographic Techniques for Measuring Fluid Flow Properties
- Choi, Y.J., Mccarthy, K.L., Mccarthy, M.J.
- Journal of food science 2002 v.67 no.7 pp. 2718-2724
- corn syrup, image analysis, magnetic resonance imaging, process control, product quality, tomato juice, tomography, viscosity
- Experimental fluid velocity profiles can be readily obtained by using tomographic techniques. Combining measurements of a fluid velocity profile with a simultaneous pressure drop permits the evaluation of rheological properties. In order to control a process and to assure product quality, it is useful to monitor the rheological properties in-line or on-line. Two tomographic techniques, magnetic resonance imaging (MRI) and ultrasonic Doppler velocimetry (UDV), were used to obtain velocity profiles for a 65.7 °Brix corn syrup solution and a 4.3 °Brix tomato juice. The UDV technique provided velocity profiles that compared well with the MRI method. For the corn syrup, the shear viscosity of 1.37 Pa-s (UDV) and 1.51 Pa-s (MRI) agreed well with the offline measurement of 1.57 Pa-s. The tomato juice was best characterized as a Bingham plastic fluid. The yield stress ranged from 4.44 Pa to 4.70 Pa, which matched well with the off-line value of 4.50 Pa. The strengths and limitations of both techniques are presented.