Holographic-Interferometer Investigation of Free-Convection from a Non-Uniformly-Heated Vertical Plate.

Holographic interferograms were made of the laminar free-convection boundary-layer produced by a vertical flat plate with a non-uniform wall-temperature distribution. A transmissive-diverging-diffuse-scene-beam technique was used. Photographs and relative positions of the features of the reconstructed scene were obtained using the primary real image, and using these photographs, boundary-layer temperature profiles and average heat-transfer rates were predicted that agree with theoretically predicted values to within 10. The focus position of the fringe pattern relative to the reconstructed plate appeared to coincide with the position relative to the actual plate of the centroid of the geometric shape defined by the wall-temperature and ambient temperature vrs. wall-position plot. Author