Efficiency of Air Microblowing Through Microperforated Wall for Flat Plate Drag Reduction

Current state and prospects of researches on the control of turbulent boundary layer by air blowing

“…In some areas of the surface, the friction drag can be reduced by around 50%, at relative low blowing coefficient values. In the presence of the blowing, the mean skin Correctness of this formula was later confirmed by experimental results [70]. Nevertheless there is also a problem in this case which is still topical; it is related with the choice of a permanent source of the air injection into a specified region on aircraft board.…”

“…It should, however, recognize that a smooth C f -distribution was observed not always. This apparently indicates that the perforated plate used in studies [70,[76][77][78] was good, but its geometry was not optimal.…”

“…In particular, Refs. [70,[76][77][78] present the dependence C f ¼f(log Re nn ) describing the variation of the local skin friction coefficient versus Re nn (Re nn is the Reynolds number defined by the boundary layer momentum thickness δ nn ); the substrate of several micro-fiber layers was used there. The discrepancy between the experimental values of C f obtained by the method of [79] and calculation results was no more than 3 À 4%, on the permeable surface too, which is a certain proof that the flow around such a wall is feasibly equivalent to the flow around the hydraulically smooth analog.…”

Effect of uniform blowing/suction in a turbulent boundary layer at moderate Reynolds number

“…for drag reduction or delaying transition to turbulence. Kornilov and Boiko (2012) reported drag reduction effects of blowing generated by a microblowing plate. Suction control, on the other hand, was examined by e.g.…”

“…The effect of blowing or suction in the plane turbulent boundary layers has been investigated not only numerically but also experimentally; see e.g. Kornilov and Boiko (2012) and Yoshioka et al (2004).…”