UNSTEADY PRESSURE MEASUREMENTS ON A BICONVEX AIRFOIL IN A TRANSONIC OSCILLATING CASCADE.

Flush-mounted dynamic pressure transducers were installed on the center airfoil of a transonic oscillating cascade to measure the unsteady aerodynamic response as nine airfoils were simultaneously driven to provide 1. 2 deg of pitching motion about the midchord. Initial tests were performed at an incidence angle of 0. 0 deg and a Mach number of 0. 65 in order to obtain results in a shock-free compressible flow field. Subsequent tests were performed at an angle of attack of 7. 0 deg and a Mach number of 0. 80 in order to observe the surface pressure response with an oscillating shock near the leading edge of the airfoil.