Simulation numérique du contrôle de l’écoulement décollé autour de profils.

Abstract

The efficiency of a synthetic jet control on the separation of a turbulent, incompressible and viscous flow around a NACA symmetrical profile, is studied numerically using two transport equations turbulent model k-ε RNG. The numerical resolution of the equations governing the physical problem, is done using the commercial code ""Fluent"" and a mesh generation software ""gambit"". The discretization of the non-linear, partial differential equations, is obtained using the finite volumes method. The lift and drag coefficient distributions and the velocity field and thus the streamlines flow field, are calculated and analyzed with and without control to find out the control efficiency. A parametric study of the jet control defined by the jet angle and its location, the jet width as well as its frequency, is carried out. By varying the angle and the location of the jet, the results show that a jet angle equal to 45° situated at 15% from the leading edge, reduce more the size of the separated region. Also, a 2% jet width for different jet angles, leads to a better control efficiency with a more reduction of the separated zone and a better increase in lift. Finally, by varying the jet frequency F+ and the jet velocity Vr, the separated zone disappears completely for a frequency equal to 2.5 and any Vr bigger than 2. The study done over different symmetrical NACA profiles, show that the control concept is as much efficient as the profile is thin producing a better increase in performances.