Vol. 18, issue 10, article # 2

Abstract:

It has been stated that the theory of similarity of turbulent flows can be propagated to an arbitrary anisotropic boundary layer. With the use of semiempirical hypotheses of the turbulence theory, it is theoretically and experimentally shown that an arbitrary anisotropic boundary layer can be considered the locally weakly anisotropic. Except for the tensor of the turbulent thermal diffusivity coefficients, the theoretical propositions of an isotropic layer (for plane-parallel flows) are carried out in the vicinity of every point of the layer. In an arbitrary boundary layer, the key turbulence parameter is the varying Monin-Obukhov number. It is established that the anisotropic boundary layer can be substituted for an effective isotropic layer. Theoretical expressions are obtained for the vertical outer scale of turbulence in the anisotropic boundary layer; the coincidence of the experimental and theoretical values of the outer scale of turbulence is shown.