An Investigation of Model Scaling Effects at Mach Numbers from 0.60 to 1.40

Abstract : Wind tunnel investigations of three scale models were conducted to determine the effects of model scaling in the subsonic and transonic flow regimes. The models were 4.7-, 13-, and 17-percent scale F-15 fighter equivalent body models. The data were obtained at Mach numbers from 0.60 to 1.40 and free- stream Reynolds numbers from 1.0 to 5.3 million for model angles of attack from 0 to 5 deg. The results show that at subsonic Mach numbers the zero-lift pressure drag coefficient of the basic configurations was a function of Reynolds number and Mach number. However, the pressure drag coefficient for the fuselage- alone configuration and the alternate wing configuration was essentially invariant with Mach number for Mach numbers below 0.90. The data obtained with the cylindrical afterbody model and integrated aft-end pressure drag increments show that the transonic interference resulting from model size was primarily confined to the contoured fuselage afterbody.