Logarithmically modified scaling of temperature structure functions in thermal convectionA. Bershadskii1, 2, K. R. Sreenivasan1 and J. J. Niemela1
1 International Center for Theoretical Physics - Strada Costiera 11, 34100 Trieste, Italy
2 ICAR - P.O. Box 31155, Jerusalem 91000, Israel
received 29 April 2004; accepted in final form 3 September 2004
published online 8 December 2004
Using experimental data on thermal convection, obtained at a Rayleigh number of 1.5 , it is shown that the temperature structure functions , where is the absolute value of the temperature increment over a distance r, can be well represented in an intermediate range of scales by , where the are the scaling exponents appropriate to the passive scalar problem in hydrodynamic turbulence and the function . Measurements are made in the midplane of the apparatus near the sidewall, but outside the boundary layer.
47.27.Te - Convection and heat transfer.
47.27.Jv - High-Reynolds-number turbulence.
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