Measurements In Particle-Laden Flows Using Magnetic Resonance Velocimetry: Time-Averaged Particle Concentration And Intrinsic Fluid Velocity
M. Bruschewski (1), W. Hogendoorn (2), D. Frank (1), W-P. Breugem (2), C. Poelma (2), S. Grundmann (1)
(1) University of Rostock, Institute of Fluid Mechanics, Rostock, Germany
(2) Delft University o f Technology, Multiphase Systems, Delft, The Netherlands
DOI:
This study presents an experimental technique based on magnetic resonance velocimetry (MRV) for time-averaged measurements in dispersed multiphase flows. The measured variables are the intrinsic velocity field of the liquid phase and its spatial distribution, from which parameters such as particle concentration or void fraction can be calculated. There are no requirements for the optical properties, but the liquid and particles must match in terms of magnetic susceptibility in order to avoid measurement errors. Common material combinations are water-glycerol and plastic particles. Relatively low measurement uncertainty can be achieved for this technique since the measurands are intrinsically averaged throughout the data acquisition process. The sources of systematic measurement errors are well understood and errors can be reduced to a minimum. In addition, the overall accuracy of this technique can be determined after the measurement by calculating the average particle concentration and the flow rate from the MRV data. These values can be verified by the target values. Therefore, this measurement technique can serve as a ground truth for numerical studies and other experimental techniques. In this study, results are presented for a glycerol-water flow containing polystyrene particles. The investigated particle-laden flow has an average particle concentration between 10 and 50% and a Reynolds number based on the apparent suspension viscosity between 800 and 5000.
