Verification of the standard model of shear stress transport and its modified version that takes into account the streamline curvature and estimation of the applicability of the Menter combined boundary conditions in calculating the ultralow profile drag for an optimally configured cylinder–coaxial disk arrangement

A modification of the popular model of shear stress transport aimed at calculating the separation flow of an incompressible viscous liquid is justified. The modification eliminates the nonphysical pumping of the vortex viscosity in the cores of large-scale vortices. It has been verified with regard to the influence of the streamline curvature on the vortex viscosity by introducing a reciprocal linear function of the turbulent Richardson number with the Isaev–Kharchenko–Usachov constant equal to 0.02.Verification is based on solving the test problem an axisymmetric steady flow about a disk–cylinder tandem with an optimally configured nose, which has an ultralow profile drag for a Reynolds number of 5 $\times$ 10$^5$. It has been shown that the Menter combined boundary conditions are valid if $y^+y$ of the wall does not exceed two.