Essentials of Supersonic Commercial Aircraft Conceptual Design

6Flat Wings in Inviscid Supersonic Flow

Although the wing and the fuselage are the most influential components contributing to aerodynamic drag, in supersonic airplane all main components for optimum efficiency of the complete vehicle must be integrated. For instance: the best airfoil section is not necessarily the section to be used with the optimum planform of the isolated wing, whereas the best planform alone is not necessarily the best to be used for the wing–body combination. In the conceptual design stage of a supersonic cruise vehicle (SCV) this problem may be solved by first conceiving the best wing shape and the best fuselage layout. Significant aerodynamic interaction effects are then identified by means of the area ruling method applied to the complete configuration. However, the design of an optimized SCV wing–body configuration is a complex exercise that will be the subject of Chapters 7 and 8.

The present chapter aims at comparing basic aerodynamic properties of three‐dimensional wings based on results generated with linearized theory. The requirement that the disturbances in the flow are infinitesimally small requires that thin and planar wings – also known as flat‐plate wings – form the initial subject of the present study. A flat‐plate wing is neither cambered nor warped or twisted, a generic shape that has been studied at length because its flow type is illustrative for lifting wings at supersonic speed in general. Pressure drag due to thickness is not taken ...