Abstract:

ESDU Aero A.02.03.02 provides equations for calculating the minimum theoretical transonic drag rise of a wing-body combination of optimum area distribution. They apply to configurations having two mutually perpendicular planes of symmetry the intersection of which define the longitudinal axis of the configuration and there may be an intake, provided there is no spillage, and a jet orifice. The configuration is defined by its nose and base areas, its length, its volume and a cross-sectional area and its distance from the nose. The base area must exceed the nose area; if that is not the case, the configuration must be reversed before making the calculations. A method is suggested for dealing with the case when the intake and jet orifice are not respectively at the nose and base of the body. The method represents the optimum area distribution as the sum of three distributions each making a separate contribution to the drag rise. Equations are given for each area distribution, each containing a factor which is presented graphically. It is possible for either the chosen value of cross-sectional area or the volume to be smaller than the optimum values; in either case one of the area distributions makes no contribution to the drag rise. A worked example illustrates the use of the method.