A comparison of various computer techniques for calculating wing pressure distributions on 3-dimensional aircraft

The prediction of wing pressure distributions on 3-dimensional aircraft configurations is a problem of great interest and importance in the development of new aircraft designs. Many techniques have been developed utilizing high speed digital computers to address this problem. These techniques differ greatly in their degree of sophistication, computer resources required, inputs and quality of results. This study examines three computer codes for predicting pressure distributions and evaluates their performance on a generalized 3-dimensional aircraft configuration relative to pressure distributions measured in a wind tunnel. In addition, the three computer codes are compared to one another in terms of computer resources required. Of the three computer codes utilized, two are considered "off the shelf" programs representing the state of the art in numerical fluid mechanics. The third program was written for this study and is more typical of some of the more specialized techniques.

An examination of the data generated using these programs indicates that all give good results at low Mach numbers, but that the performance of each is impaired to varying degrees by increasing Mach number. It is also observed that dramatic savings in computer resources result through the use of a more specialized program. It is therefore held that by carefully evaluating the needs of a particular problem and selecting a computer program to match these needs, a significant

saving in time and computer resources can be obtained while maintaining the quality of the results.