An Optimization Tool for Axisymmetric Bodies of Minimum Drag
H. Schweyher, Th. Lutz and S. Wagner
Proceedings 2nd International Airship Conference, Stuttgart/Friedrichshafen, July 3-4, 1996
This paper decribes a method for the numerical shape optimization of axisymmetric minimum-drag bodies using the Evolution Strategy as optimization algorithm. The flowfield about the body of revolution is modeled by a linearly varying distribution of sources and sinks on the body axis. Evaluation of the corresponding streamfunction yields the contour and the inviscid velocity distribution on the body. The aerodynamic drag is calculated by application of a boundary-layer method based on the inviscid velocity distribution on the body surface. The optimization method combines different designs to a new one by recombination and mutation and uses an objective function for calculating its quality. An example for the application of the new optimization tool is presented.