Approximate Theory for Calculation of Lift of Bodies, Afterbodies, and Combinations of Bodies

摘要

An expression is developed for the lift of a slen%er afterbody in terms of the 'slender-body' approximate potential at the after end in conjunction with a suitably calculated value of the potential at the forward end. The failure of the usual 'slender-body' theory to predict any lift on a slender cylindrical afterbody is thereby corrected. The same expression is used to compute the part of the interference lift generated by the presence of a neighboring body, due to the interference upwash. Another expression is developed to compute the remainder of the interference lift, due to an interference pressure gradient. The lift is determined for a cone-cylinder body, a cylindrical afterbody of a slender wing body combination, and three combinations of bodies to illustrate the method.