Accession Number : ADP002947

Title :   Diagnostic Algorithms for Contour Dynamics,

Corporate Author : PITTSBURGH UNIV PA DEPT OF MATHEMATICS AND STATISTICS

Personal Author(s) : Overman,E. A. , II ; Zabusky,N. J.

Report Date : FEB 1984

Pagination or Media Count : 19

Abstract : The goal of large scale numerical simulations (numerical experiments) is to obtain a quantitative understanding of complicated nonlinear dynamical processes. A proper picture or graph can spark in-the prejudices of conservative intuitions. Diagnostic algorithms and their graphs are particularly useful in the contour dynamics model for studying two-dimensional fluid dynamics. This is because the 2D densities are replaced by contours bounding piecewise-constant density regions (i.e., 1D curves). Thus our diagnostic parameters are functions of one variable, the arc length along each curve, and their graphs are 2D. We discuss and illustrate some time-dependent properties of planar curves, including the spatial plot, low order moments, perimeter, curvature, and Fourier transforms. We also apply these techniques to contours obtained from finite-difference representations of continuum systems.

Descriptors :   *Fluid dynamics, *Diagnosis(General), *Algorithms, *Graphs, Contours, Distribution curves, Mathematical models, Nonlinear systems, Density, Time dependence, Plotting, Spatial distribution, Fourier transformation, Moments, Plasmas(Physics), Ionospheric models, Dynamics, Finite difference theory, Incompressible flow

Distribution Statement : APPROVED FOR PUBLIC RELEASE