SIMULATION OF THICK TURBULENT BOUNDARY LAYER VIA JET ARRAY

Experimental studies directed to qualify the potential of simulation of an equilibrium (by Klauser) thick incompressible turbulent boundary layer on a flat plate of limited length with the help of an array of jets were carried out. It is shown that in the range of flow parameters and the mass flow rates of blowing under consideration the air jets through some rows of the holes with different diameter increase substantially the thickness of turbulent boundary layer within a comparatively small distance of the blowing region. In most cases studied, the mean and fluctuating characteristics of the boundary layer reach values specific for naturally developed turbulent boundary layer at downstream distances of about 22 thickness of regular boundary layer. Mean velocity profiles in the logarithmic part of the artificially thickened boundary layer are described by the law-of-the-wall variables with a good accuracy and generalized by a single dependence with the help of empiric velocity scale for the outer region. Disturbance characteristics of the flow are also close to those in the canonic boundary layer. However, as the blowing intensity grows, a systematic deviation of the disturbance streamwise velocity from the canonic values is observed, which indicates the limitation of the present approach and points out the need of further refinement of the method of simulation under consideration.

Keywords:
experimental simulation, higher Reynolds numbers, incompressible turbulent boundary layer, flat plate, transverse jets, blowing coefficient. 
УДК 532.526.4 + 532.522+532.526.72 +533.6.011.32

SIMULATION OF THICK TURBULENT BOUNDARY LAYER VIA JET ARRAY