Near wake of a circular cylinder submitted to blowing - I Boundary layers evolution

The dynamical and thermal behavior of the flow around a circular cylinder s ubmitted to blowing is experimentally investigated. The blowing is applied through the whole surface of a porous cylinder submitted to a heated turbul ent main fluid in cross-flow. Velocity, pressure and temperature profiles a re determined for different injection rates and main flow temperatures for Reynolds numbers ranging from 3900 to 14000. The velocity and temperature p rofiles are similarly modified with the blowing, while the injection thicke ns the boundary layers and modifies their shape. These evolutions lower the transfer coefficients, both dynamical (shear stress) and thermal (heat tra nsfer), and are dependent on the location around the cylinder. The blowing impact on the wall temperature is also quantified, exibiting an excellent e ffectiveness of the cooling with blowing. (C) 2001 Elsevier Science Ltd. Al l rights reserved.