INVESTIGATION OF UNSTEADY TRANSONIC FLOW FIELD ABOVE LAMINAR AIRFOIL BY PIV METHOD

摘要

Experimental investigation of flow field above a laminar airfoil in a transonic wind tunnel was conducted. The aim of the research was to provide a quantitative information about the shock position for various angles of incidence at Mach number = 0.7. The flow field in a test section of high speed blow down wind tunnel was investigated by means of Particle Image Velocimetry (PIV). The resulting instantaneous vector velocity field was processed in order to determine the variation of shock position above the airfoil. As expected, the shock moved closer to the leading edge while the angle of incidence was increased. More interestingly, the experimental data revealed an increase in shock oscillation amplitude for angle of incidence between 3° and 5°. Experiments allowed to quantitatively describe the transonic flow field above the airfoil by non-intrusive method.