Wake Integration for Three-Dimensional Flowfield Computations: Applications

Abstract

A momentum balance approach is used to extract lift and drag from flowfield computations for wings and wing/bodies in subsonic/transonic flight. The drag is decomposed into vorticity, entropy, and enthalpy components that can be related to the established engineering concepts of induced drag, wave and profile drag, and engine power and efficiency, This decomposition of the drag is useful ill formulating techniques for accurately evaluating drag using computational fluid dynamics calculations or experimental data, A formulation for reducing the size of the region of the crossflow plane required for calculating the forces is developed using cutoff parameters for viscosity and entropy. This improves the accuracy of the calculations and decreases the computation time required to obtain the results, The Improved method is applied to a variety of configurations, including an elliptic wing, the M6 wing, the W4 wing-body, the M165 wing-body- foreplane, and the Lockheed Wins A. The accuracy of the force calculations is related to various aspects, including the axial position of the downstream crossflow plane, grid type (structured or unstructured), grid density, flow regime (subsonic or transonic), and boundary conditions