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ISSN Online: 2377-424X

ISBN Print: 0-89116-299-2

International Heat Transfer Conference 7
September, 6-10, 1982, Munich, Germany

VELOCITY MEASUREMENTS IN A TURBULENT NATURAL CONVECTION BOUNDARY LAYER

Get access (open in a dialog) DOI: 10.1615/IHTC7.3290
pages 305-309

Résumé

A number of authors have pointed out that the experimental data for a turbulent natural convection boundary layer on an isothermal plane surface reported by the first author above in 1967, does not satisfy an integral energy balance. Examination of the only two other complete sets of data for this flow show that they are also inconsistent. The most likely source of the inconsistency is in the measurement of the mean velocity profiles and new measurements using a counter-based laser Doppler anemometer system have been undertaken to check the velocity data. The data from the LDA system were recorded digitally and checked for the influence of possible bias errors. However, it was found that despite the high levels of turbulence recorded, the correction produced by residence time weighting was only 2-3%. The new velocity data are compared with the earlier data and an integral energy balance is drawn up which shows that the present data are reasonably consistent although the mean velocity profile data still shows some scatter.