Calculation of unsteady transonic flows with shocks by field panel methods

Abstract

Fig. 2 Design chart to determine K B KB(W) f°r no afterbody. for negative afterbody from Fig. 3 K B(Hr} for negative afterbody as a function of afterbody length. (If you relabel the abscissa as R = P+2 9 this figure is applicable for all P and D with 0 <R < 2.) upper-half straight line from specified values of D n and £/C r , K B(W} then can be looked up from a lower-half curve for a given B. For example, Fig. 2 yields K B( W)~2 and D «1.25 for £>" = 1, £/C r = -0.2, andB-+<x>.Variation of K B(W) with respect to afterbody length is illustrated in Fig. 3 for the full range of B values. Note that for a fixed B the dependence of K B( W) on R is linear if R is less than or equal to unity. ConclusionClosed-form formulas have been presented for the interference factors K B(]V) for a body in the presence of a wing at supersonic speeds when a finite afterbody is introduced. In addition, formulas for K B(W) 's have been obtained for situations when the base of the body is forward of the trailing edge of the exposed root chord (negative afterbody). These formulas are valid subject to the restrictions inherent in the formulation of Ref. 2. RemarksSimilar to K B( W} , the body longitudinal center-of-pressure location can be determined in closed form. This work is currently in progress and will be reported later.