A Geometry Package for Generation of Input Data for a Three-Dimensional Potential-Flow Program

摘要

The preparation of geometric data for input to three-dimensional potential -flow programs is a very tedious, time-consuing (and therefore expensive) task. This report describes a geometry package that automates and simpli¬fies this task to a large degree. Input to the computer program for the geometry package consists of a very sparse set of coordinate data, often with an order of magnitude fewer points than required for the actual poten¬tial flow calculations. Isolated components, such as wings, fuselages, etc. are paneled automatically, using one of several possible element distribu¬tion algorithms. Curves of intersection between components are calculated, using a hybrid curve-fit/surface-fit approach. Finally, intersecting components are repaneled so that adjacent elements on either side of the intersection curves line up in a satisfactory manner for the potential-flow calculations. The geometry package has been incorporated into the NASA Langley version of the 3-D lifting potential flow program and it is possible to run many cases completely (from input, through the geometry package, and through the flow calculations) without interruption. Use of this geometry package can significantly reduce the time and expense involved in making three-dimensional potential-flow calculations.