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ISSN Online: 2377-424X

International Heat Transfer Conference 4
August 31 - September 5, 1970, Paris-Versailles, France

EXPERIMENTAL DETERMINATION OF THE TURBULENT PRANDTL NUMBER IN A DEVELOPING TEMPERATURE BOUNDARY LAYER

Get access (open in a dialog) DOI: 10.1615/IHTC4.1900
pages 1-11

Abstrakt

Measurements of Prt were performed at five stations in a turbulent temperature boundary layer developing along a flat plate with a stepwise wall-temperature variation. The Prt values were calculated from the measured mean quantities as well as from the direct measurements of uv and vθ. The results agree reasonably well. A variation of Pr t across the boundary layer is found, clearly showing the invalidity of the usually assumed Reynolds analogy (Prt = 1).
For a developing temperature boundary layer it is impossible, except very close to the wall (y+ < 30), to indicate a universal Prt profile, which throws some doubt on the usefulness of Prt as a parameter to describe turbulent heat transfer.