%0 Journal Article %T Quantitative Visualization of the Thermal Boundary Layer of Forced Convection on a Heated or Cooled Flat Plate with a 30° Leading Edge Using a Mach-Zehnder Interferometer %A Jun Liu %A Atsuki Komiya %J Journal of Flow Control, Measurement & Visualization %P 99-116 %@ 2329-3330 %D 2022 %I Scientific Research Publishing %R 10.4236/jfcmv.2022.104007 %X This study focuses on the experimental measurements of the heat transfer coefficient over a flat plate with a 30กใ leading edge. Under forced convection by a hot/cold air and flow over a cooled/heated flat plate, the thermal boundary layer and its thickness are quantitatively visualized and measured using a Mach-Zehnder interferometer. In addition, the variation in the local heat transfer coefficient is evaluated experimentally with respect to the air flow velocity and temperature. Differences within the heat transfer performance between the plates are confirmed and discussed. As a result, the average heat transfer performance is about the same for the heated plate and the cooled plate under all air velocity conditions. This contrasts with the theoretical prediction in the case of low air velocity, the reason considered was that the buoyancy at the 30กใ leading edge blocked air from flowing across the surface of the plate. %K Thermal Boundary Layer %K Forced Convection %K Heat Transfer Coefficient %K Visualization %K Mach-Zehnder Interferometer %U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=120252