Parametric Bi-Cubic Surface Patch for Computer Aided Geometric Desigh of Aircraft and/or Other Three-Dimensional Geometries

摘要

A FORTRAN program was developed to fit smooth surfaces to the component parts of an arbitrary aircraft configuration or any three dimensional geometry. The basic surface element used for this fit is a bicubic surface patch. Once the geometry was replaced by a set of patch equations, various kinds of calculations which require a three dimensional mathematical description of the surface can be performed easily. The second part of the code generates orthographic views of the given geometry on a calcomp drum plotter or on a Tektronix screen. The last part of the program generates cross sectional plots at any desired orientation through the given configuration. Also this module can be used to generate cross sectional areas, intermediate sections and other geometric details of the given configuration. The input data is oriented mainly towards aircraft geometry. But the code can be efficiently used for representing any arbitrary surface or a combination of both.