CHARACTERISTICS OF TURBULENCE
WITHIN AN INTERNAL BOUNDARY LAYER
R. A. ANTONIA AND R. E. LUX TON^
Department of Mechanical Englnccrlng
Uniwrsfty 4Svdne9, S w y , A ~ f i a l i a
1. INTRODUCTION
At the first conference in this series held in Oxford, England, in 1958, G. 1.
Taylor (1959) surveyed “The present position in the theogy of turbulence
diffusion..’ He began by describing his 1913 work as a meteorologist on the
sailing whaler Scoria (Taylor, 1915) from which he flew kites holding temperature, humidity, and pressure recorders.* ‘ * It was not possible to get to any
great height with this equipment but the very rapid changes in temperature
with height which occur in the first few hundred feet in this part of the world
made results of interest in spite ofthis limitation. The records showed that in
most cases the temperature of the air was Buch higher at a few hundred feet
than at sea level. This was clearly due to the fact that warm westerly winds
flowing off the American continent during sununw were rapidly cooled
when they reached the icebergladen waters off Newfoundland.” Schematically what was happening was that an ,, internal . . cold boundary layer was
forming under the “external” warm boundary layer. Tbc interface between
the two layers defined the distance to which information about the new
surface condition had diffused and the rate of growth of the internal layer
indicated the rate at which the new information was propagating.
Since Taylor led the way into this important area of information diffusion
in a boundary layer-or more particularly, the response of a boundary layer
flow to a change in boundary condition-many have followed because of the
relevance of the problem in many fields. In this conference we are especially
concerned with the atmosphere and this exists, broadly speaking, on three
scales. Our present problem is of interest to the micrometeorologist in the
lowest few meters of the atmosphere as the upwind terrain-“fetch” as he
calls it-may influence heat and moisture transfer from the surface (Bradley,
’ Prcserrr address: Department of Mechanical Engineering, University of Adelaide, Adelaide,
’ G. 1. Taylor’s writings have been paraphrased on so many occasions that we wish here to
South Australia.
do him the courtesy of including his own evocative description.
263
WITHIN AN INTERNAL BOUNDARY LAYER
R. A. ANTONIA AND R. E. LUX TON^
Department of Mechanical Englnccrlng
Uniwrsfty 4Svdne9, S w y , A ~ f i a l i a
1. INTRODUCTION
At the first conference in this series held in Oxford, England, in 1958, G. 1.
Taylor (1959) surveyed “The present position in the theogy of turbulence
diffusion..’ He began by describing his 1913 work as a meteorologist on the
sailing whaler Scoria (Taylor, 1915) from which he flew kites holding temperature, humidity, and pressure recorders.* ‘ * It was not possible to get to any
great height with this equipment but the very rapid changes in temperature
with height which occur in the first few hundred feet in this part of the world
made results of interest in spite ofthis limitation. The records showed that in
most cases the temperature of the air was Buch higher at a few hundred feet
than at sea level. This was clearly due to the fact that warm westerly winds
flowing off the American continent during sununw were rapidly cooled
when they reached the icebergladen waters off Newfoundland.” Schematically what was happening was that an ,, internal . . cold boundary layer was
forming under the “external” warm boundary layer. Tbc interface between
the two layers defined the distance to which information about the new
surface condition had diffused and the rate of growth of the internal layer
indicated the rate at which the new information was propagating.
Since Taylor led the way into this important area of information diffusion
in a boundary layer-or more particularly, the response of a boundary layer
flow to a change in boundary condition-many have followed because of the
relevance of the problem in many fields. In this conference we are especially
concerned with the atmosphere and this exists, broadly speaking, on three
scales. Our present problem is of interest to the micrometeorologist in the
lowest few meters of the atmosphere as the upwind terrain-“fetch” as he
calls it-may influence heat and moisture transfer from the surface (Bradley,
’ Prcserrr address: Department of Mechanical Engineering, University of Adelaide, Adelaide,
’ G. 1. Taylor’s writings have been paraphrased on so many occasions that we wish here to
South Australia.
do him the courtesy of including his own evocative description.
263