S. Ashkenazi et V. Steinberg, Spectra and statistics of velocity and temperature fluctuations in turbulent convection, PHYS REV L, 83(23), 1999, pp. 4760-4763
Direct measurements of the velocity in turbulent convection of SF6 near its
gas-liquid critical point by light scattering on the critical density fluc
tuations were conducted. The temperature, velocity, and cross frequency pow
er spectra in a wide range of the Rayleigh and Prandtl numbers show scaling
behavior with indices, which are rather close to the Bolgiano-Obukhov scal
ing in the wave number domain. The statistics of the velocity fluctuations
remain Gaussian up to the Reynolds numbers of 10(5).