Numerical simulation of interaction of a microjet array with a turbulent shear flow

Results of numerical investigations of the characteristics of a turbulent boundary layer in the case of air blowing through a smooth flat perforated surface with a single hole and also through a similar surface with a group of staggered holes 0.18 mm in diameter (d/δ=0.0072) in a low-velocity flow are reported. The Reynolds number Re** based on the momentum thickness δ** ahead of the perforated region is 2600. The blowing coefficient C_b is varied in the interval from zero to 0.0438. The influence of some geometric parameters, in particular, the distance between the hole centers, on the properties of the transverse shear flow for identical intensities of blowing in situations with one hole and with a group of holes is analyzed. All observations reveal stable reduction of local friction whose value varies depending on the number of holes and their arrangement on the surface.