Three-dimensional visualization and measurement of temperature field usingliquid crystal scanning thermography

A Liquid Crystal Scanning Thermography (LCST) technique is developed and im plemented to visualize and measure three-dimensional temperature fields. Re sults tire reported for natural convection in a differentially heated verti cal cavity. Experiments are conducted under steady state conditions at Rayl eigh numbers of about 10(4) with glycerin as the working fluid. The scannin g arrangement is described in detail together with the calibration scheme, and image processing routines that enable the processing of the thermograph s and extraction of quantitative temperature information from them includin g local and global heat transfer rates. The resultant temperature fields an d Nusselt number values are computed and validated against both standard em pirical relations and numerical predictions. To date, LCT hors not been use d to determine Nusselt number,for enclosed fluid systems. The ability of LC ST to perform this task makes this novel experimental technique a useful to ol.