Book Description

An investigation was made in the Langley stability tunnel to determine the effect of airfoil profile of symmetrical sections on the rolling derivatives of three untapered wings having 45 deg sweepback. The wings had the following profiles normal to the leading edge: biconvex (12% thick), NACA 65 sub 1 -012, and NACA 0012. The AR for each wing was 2.61. Calculations were made to determine the effect of different wing profiles on the stability boundaries and motions at subsonic speeds of a typical transonic airplane configuration. Results indicate that increasing the sharpness of the leading edge of the airfoil decreased the range of lift coefficients over which the derivatives maintained their initial trends and usually decreased the maximum values of the derivatives obtained in the unstalled range. Results of the calculations of the dynamic stability of the airplane configuration show only small changes in stability due to changes in airfoil profile.