|dc.description.abstract||Theoretical studies of turbulent natural convection phenomena have for some time been hindered by a lack of any reliable experimental data. The primary objective of this investigation was the provision
of such data... Mean
velocity and temperature profiles have been measured. These are in
general agreement with the only previous results which were obtained
in 1921, but show substantial disagreements when compared with theoretical
predictions. Distribution of frequency and amplitude in the turbulent
temperature fluctuations have also been measured.
In addition to the investigation of the turbulent boundary layer,
a considerable number of experiments have been carried out on laminar
and transitional boundary layers. The work on the laminar boundary layer
was prompted by the discovery of the effect of a vertical temperature
gradient outside the boundary layer. New similarity solutions to the
laminar boundary layer equation have been derived for a wide range of
conditions. These solutions suggest that the presence of a temerature
gradient outside the boundary layer can cause instability, throughout
the whole laminar region. Experimental measurements of local heat transfer
rates and temperature profiles tend to confirm the theoretical
Measurements in a transitional boundary layer show the variation
of the local heat-transfer coefficient, together with the development of
the mean temperature profiles and the temperature fluctuations.
In the derivation of the theoretical results, a new method for
the numerical solution of coupled, non-linear differential equations on
a digital computer, as been developed. A comparison is made between
this method and the more commonly used method of Bunge-Kutta.