ON THE TEMPERATURE-FIELD MICROSTRUCTURE IN THE VISCOUS HEAT-CONDUCTION RANGE

Estimates are obtained of the constant C(THETA) in the Oboukhov-Corrsin "2/3 law" for the temperature structure function. The mean value of C(THETA) retrieved from the temporal structure function D(tt)(tau), is equal to 4.5 +/- 0.4. The Yaglom relation yielded C(THETA) = 3.2. An attempt was made to explain the scatter of experimental estimates of C(THETA) by the influence of the "outer" intermittency which is present in the unstably stratified boundary layer. Making use of thermal noise filtration by the two-sensor method allowed to study the behavior of temperature spectral functions in the dissipative range. The dependence was demonstrated of the dissipative spectral slope on the intensity of temperature fluctuations in the inertial subrange.