The Prandtl and Rayleigh number dependences of the Reynolds number in turbulent thermal convection following from the unifying theory by Grossmann and Lohse [J. Fluid Mech. 407, 27 (2000); Phys. Rev. Lett. 86, 3316 (2001)] are presented and compared with various recent experimental findings. This dependence Re(Ra,Pr) is more complicated than a simple global power law. For Pr=5.5 and 108<Ra<1010 the effective or local power law exponent of Re as a function of Ra is definitely less than 0.50, namely, Re~Ra0.45, in agreement with Qiu and Tong¿s experimental findings [Phys. Rev. E 64, 036304 (2001)]. We also calculated the kinetic boundary layer width. Both in magnitude and in Ra scaling it is consistent with the data.
|Number of pages||6|
|Journal||Physical review E: Statistical physics, plasmas, fluids, and related interdisciplinary topics|
|Publication status||Published - 2002|