EXP ~ INVESTIGATION OF THE OSCIIJJUING FORCES AND MOMENTS ON A TWO-DIMENSIONAL WIXG EQUIPPED WITH

Results are presented of am experimental investigation in the Langley 2- by k-foot flutter research tunnel on the oscillating forces and moments on a two-dimensional wing eqplpped with an oscillating circuler-arc spoiler. The forces and moments and their phase sngles with respect to spoiler motion were determined from measurements of the instsmtameous pressure distribution and the nature of the flow over the wing was studied with schlieren photographs. Data are presented for Reynolds ntiers from 1.3 x 106 to 6.3 x 1($, Mach numbers from 0.20 to 0.82, and reduced frequencies from O to 0.92. The results of this study indicate that the force and moment coefficients and their phase angles are affected in a complex manner by Reynolds n~er, Mach number, and reduced frequency