Investigation of Influence of Air Blowing in a Turbulent Boundary Layer By Means of Digital Particle-Based Flow Visualization

It was experimentally studied the possibility of the digital particle-based flow visualization technique (PIV) of application to investigate the properties of an incompressible turbulent boundary layer modified by air blowing through a microperforated surface. Experimental setup, including the optical measurement system is described. The advantages of the PIV method based on the proposed optical system are discussed. There are also presented the experimental data on the friction reduction and on the changes of the spatial structure and of the turbulence characteristics of the boundary layer under the influence of injection, obtained by this method. It is shown that the results gained generally match the measurements performed by alternative techniques and the basic reasons for the observed discrepancies are revealed

COMPUTATION OF TWO-DIMENSIONAL INCOMPRESSIBLE TURBULENT BOUNDARY LAYER FLOWS WITH EQUILIBRIUM AND NONEQUILIBRIUM TURBULENCE MODELS

Two-dimensional incompressible turbulent boundary layer flows over a flat plate were predicted using turbulent boundary layer equations. Reynolds stresses were calculated using Cebeci-Smith, Baldwin-Lomax, and Johnson-King eddy viscosity models. Computational results of mean-flow properties based on Cebeci-Smith model and Baldwin-Lomax model are in excellent agreement with experimental data, and, those based on Johnson-King model are not as accurate as the other two models.