Paper 96-2482. Presented at the AIAA 14th Applied Aerodynamics Conference, June 1, 1996, pages 815-829. Copyright © 1996 by the authors. Published by the American Institute of Aeronautics and Astronautics, Inc.
This paper examines the analytical, experimental, and computational aspects of tlie determination of the drag acting on an aircraft in flight, with or without powered engines, for subsonic/transonic flow. Using a momentum approach, the drag is represented by an integral over a cross-flow plane at an arbitrary distance behind the aircraft Asymptotic evaluation of tlie integral shows tlie drag can be decomposed into three components corresponding to streamwise vorticity and variations in entropy and stagnation enthalpy. These are shown to be related to tlie established engineering concepts of induced drag, wave drag, profile drag and engine power and efficiency. This decomposition of the components of drag is useful in formulating techniques for accurately evaluating drag using computational fluid dynamics calculations or experimental data.