Multiphase Flow Quantitative Visualization

Full-field quantitative visualization of multiphase flows requires the introduction of high resolution noninvasive methods. Two such methods are presented: Scanning Confocal Microscopy (SCM), and Magnetic Resonance Imaging (MRI). SCM has higher resolution, contrast, and depth discrimination than conventional light microscopy. A modern SCM system operating in reflection mode performs optical sectioning of 3D surfaces with submicron resolution at video rates, and this suggests its use in reconstructing evolving interfaces. MRI is a versatile tool for mapping the distribution of liquids (primarily water) in 3D space and for performing multicomponent velocity measurements. MRI is the only practical solution in systems that are strongly refracting or opaque to visible light. SCM is employed (for the first time) to image frost growing under ambient conditions, and MRI is used to visualize phase change and to measure local velocity in natural convection in water-saturated porous media. These problems reflect the research interests of the author but also serve to show the potential of the techniques in probing multiphase flows containing complex interfaces.