Holographic interferometric study of natural convection along a vertical plate

The full range of information pertaining to holographic interferometry has been documented. The phenomenon of light interference is explained and subsequently used to develop the equation of ideal interferometry. The non-ideal characteristics of interferometric research are discussed and the corresponding correction terms are presented. Moreover, thorough consideration is given to the configuration, adjustment and operation of a holographic interferometer. The influence of the experimental apparatus on the accuracy of the interferometric results is addressed. The use of holographic interferometry in research is demonstrated via investigation of natural convection heat transfer along a vertical isothermal surface. The procedure for analysis of the resulting interferogram for determination of local surface temperature and Nusselt number is given. The analysis procedure presented in this thesis differs from traditional methods in that both bright and dark fringes are used, and a linear polynomial is used to extrapolate the surface temperature and temperature gradient. Additionally, a statistical method of determining the number of interferometric data sets used to produce the first order temperature profile is proposed. The analysis presented strives to generalize the procedure in order to create an analysis method which can be utilized in other applications. The interferometric results are compared to thermocouple measured surface temperature and similarity solution to determine their accuracy. It was found that using both fringe types provides sufficient data density to support accurate first order extrapolation of the results. The average error in the Nusselt numbers thus obtained was 6.81 percent, which is within the expected range for the number of fringes in the evaluated interferogram.