Investigation of NACA 0012 Airfoil Periodic Flows in a Transonic Wind Tunnel

An experimental study of static and dynamic pressure distributions over a NACA 0012 airfoil in the two-dimensional test section 0.8 × 0.4-meter of a transonic wind tunnel is presented. Tests are conducted at freestream Mach numbers from 0.35 to 0.89, and angle of attack between −2.0 and 15, and Reynolds number based on the airfoil chord length of 3.0 million. Tests are performed at boundary-layer transition free and transition fixed at 5% chord length conditions. Firstly, sublimating naphthalene visualization is performed to locate the transition position of the boundary layer over the airfoil at upper surface. Secondly, the chordwise static pressure distributions with transition fixed are validated by well-documented data in the literature. Thirdly, the dynamic pressure data at Mach numbers from 0.60 to 0.89 are analyzed. Finally, a numerical simulation at freestream Mach numbers from 0.82 to 0.89 are done. The unsteady computation results show a close trends as experimental measurements.