Numerical Generation of 3D Curvilinear Coordinate Systems and Computational Grids for Aircraft Configurations.
Final technical rept. May 82-Jul 84,
LOCKHEED MISSILES AND SPACE CO INC PALO ALTO CA RESEARCH AND DEVELOPMENT DIV
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This report describes the progress in research on the properties of the Lockheed 3-D elliptic grid generation procedure and improvement of its capabilities for treating complex geometric features characteristic of aircraft configurations. Two areas of weakness in the original technique relate to the fundamentally important capability for generating curved-surface grids as a necessary prerequisite for generating 3-D space grids. These weaknesses were 1 difficulties associated with the limitations of Cartesian coordinates for describing convex surfaces and problems in controlling the orthogonality of the grid near boundaries. The bulk of the first years research resulted in development of a generalized system of elliptic grid generation equations that allow both the surface and the grid to be described in terms of an arbitrary system of curvilinear coordinates. Research in the second year was concerned primarily with the problem of grid orthogonality near boundaries. Three approaches investigated to improve the control that the user has over the angle at which grid lines intersect the boundaries were 1 refinement of the original techniques 2 development of techniques for marching from a given boundary using the angle as an initial condition and 3 derivation of a fourth-order system that permits additional boundary conditions on the grid intersection angle. Keywords Computational grid generation Elliptic grid generation.
- Theoretical Mathematics