Force Diagnostics of Aerodynamic Bodies Based on Wake-Plane Data

The conventional method of using a balance to measure lift and drag on a model in a wind tunnel only provides information about the total quantities of these force components. Wake-survey analysis is a different technique developed for determining aerodynamic force on a body. Compared with the balance measurement, it provides a great deal of information about decomposed constituents and it clarifies the source of the aerodynamic force, but it also requires considerable work. In 1989, J.Z. Wu and J.M. Wu developed a unique theory, based on vorticity, for determining sources of aerodynamic force on a body from wake-plane data. They applied an integration by part to the original momentum balance in a control volume, and obtained an exact result expressed only in terms of the wake-plane data. In this thesis, the above theory is applied to the near-wake data behind a delta wing, obtained from NASA Langley Research Center. The total lift and drag coefficients are calculated and compared to the experimental results. Four normal force constituents and four axial force constituents are computed and plotted along the span. Finally, total lift and drag distributions along the span are determined, and aerodynamic efficiency (lift to drag ratio) is identified for various span locations.