Aerodynamic Characteristics in Pitch of a Series of Cruciform-Wing Missiles with Canard Controls at a Mach Number of 2.01

An investigation has been conducted in the Langley 4- by 4-foot supersonic pressure tunnel at a Mach number of 2.01 to determine the static longitudinal stability and control characteristics of a series of missile configurations with canard controls at angles of attack up to about 28 deg. The missiles had cruciform wings and canard surfaces of delta plan form with 70 deg.swept leading edges. Five bodies having fineness ratios of 19.1, 17.7, 16.7, 15.7, and 14.8 were investigated. The results of the investigation indicated a large nonlinear variation of pitching moment with angle of attack for the body of largest fineness ratio that was progressively reduced by decreasing the fineness ratio until it was essentially eliminated for a body of fineness ratio 14.8. The increased linearity of the moment curve would make it possible to reduce the margin of stability so that, for a given canard size and deflection, a higher trim angle of attack might be obtained for the shortest missile than for the longest missile. The pitching-moment results indicated that methods of prediction which assumed linear variations with angle of attack for the wing-alone and wing-plus-interference characteristics were adequate for angles of attack up to about 12 deg. At higher angles of attack it was evident that the characteristics of these components were nonlinear and that more refined methods would be required for adequate prediction.