The wave drag of non-lifting combinations of thin wings and 'non-slender' bodies

Abstract

The methods of wave-drag estimation known as the area rule and transfer rule are restricted to non-lifting combinations of thin wings and slender bodies. The Lomax-Heaslet multipole method is applicable to configurations with 'non-slender' fuselages, represented by an axial distribution of multipoles. However, it is not entirely satisfactory and an alternative multipole method is presented here. This is based upon the assumption, fundamental to the area rule and the transfer rule, that the effect oil the wave drag of the interference velocity potential, due to the interaction between the exposed wing and the fuselage, is negligible. An investigation of the validity of this fundamental assumption based on existing theoretical and experimental results, is given. The application of the multipole method to fuselage design for low combination wave drag is discussed with special reference to an elliptic wing-body combination.