Publicado 6 números por año
ISSN Imprimir: 1948-2590
ISSN En Línea: 1948-2604
THE REFINED COLES' LAW OF THE WAKE
SINOPSIS
The Reynolds-average flow of incompressible fluid in a two-dimensional turbulent boundary layer is considered. The layer is supposed to be sufficiently thin up to the separation point, so that only the Reynolds' shear stress tangential to the body surface affects the layer. In other words, the flow considered is similar to the plane-parallel flow, when the "smooth" separation is realized. The new refined modification of Coles' function of the wake is proposed. This refined function approximates well the mean-velocity profile and skin-friction coefficient. The formparameter H maximum value equal to 3.89 is reached at the "smooth" separation regime. The derivation of the wake law is based on the fundamental assumption of the one-parameter nature of the velocity defect profile, which is repeatedly confirmed experimentally. It is shown that the proposed wake function near separation section has a velocity profile zone where the well-known "half power law" is fulfilled. However, in the section of a "smooth" separation such a zone almost disappears. Results of this study are confirmed by the comparison with the experimental data.