An experimental and theoretical study of transonic flow about the NACA 0012 airfoil

In this paper, experimental results of wind tunnel measurements for conventional, symmetrical airfoil NACA 0012 obtained from the trisonic wind tunnel of Aeronautical Institute VTI Zarkovo, Belgrade are presented. The measurements of lift coefficient and lift-curve slope are presented. The results were obtained from tests and integrations of surface static-pressure data over a model of the NACA 0012 airfoil section. Data for the NACA 0012 airfoil were obtained for a free-stream Mach number range of 0.25 - 0.8 and a chord Reynolds number range of 2 x 10(6) to 25 x 10(6). The essential results of these measurements along with the results from other authors are presented and evaluated. The principal factors which influence the accuracy of two-dimensional wind tunnel test results are analyzed. The influences of Reynolds number, Mach number and wall interference with reference to solid and how blockage (blockage of wake) as well as the influence of side-wall boundary layer control are analyzed.