THREE-DIMENSIONAL FLOW AND TEMPERATURE DISTRIBUTION IN RAYLEIGH-BENARD CONVECTION USING THERMOCHROMIC LIQUID CRYSTALS AND DIGITAL IMAGE PROCESSING

The application of Thermochromic Liquid Crystals (TLC) suspended in glycerol to the investigation of Rayleigh-Bénard convection is described. Multiple-exposure images of TLC particles in cross sections parallel to the long and short sides of an enclosure are recorded on transparency film using a flash equipped with a collimator, yielding a thin light sheet. Images are then digitized and split into hue-saturation-intensity components; hue is converted into temperature using a previously obtained calibration curve, while the intensity component (B/W image) is processed by the AEA software VISIFLOW using a correlation method to give in-plane velocities. Planar distributions can then be interpolated to reconstruct the three-dimensional flow and temperature fields, giving Tomographic Particle Image Velocimetry and Thermography (TPIVT). 1