Statistical properties of a turbulent boundary layer affected by grid-generated turbulence (analysis of spatial development by means of direct numerical simulation)

Abstract

The effects of grid-generated turbulence on a turbulent boundary layer are investigated by means of a direct numerical simulation (DNS). A square turbulence-generating grid, on which the velocity components are set to zero, is numerially constructed near the entrance to a rectangular parallelepiped domain. The nonslip condition is applied to the lower boundary to develop a turbulent boundary layer downstream of the turbulence-generating grid. The fractional step method is used to solve the governing equations. The results show that streamwise and vertical turbulence intensities and Reynolds stress normalized by the inner parameters are suppressed in the log-law region by the grid turbulence. © 2011 The Japan Society of Mechanical Engineers.