Accession Number:

ADA193580

Title:

Vortex Dynamics of Coherent and Chaotic Structures (Including Algorithms for Computer Simulations and Diagnosis).

Descriptive Note:

Final rept. 1 Sep 84-31 Aug 87,

Corporate Author:

PITTSBURGH UNIV PA DEPT OF MATHEMATICS AND STATISTICS

Personal Author(s):

• Zabusky, N. J.

Report Date:

1987-12-20

Pagination or Media Count:

5.0

Abstract:

Substantial contributions have been made to understanding of fundamental processes in two-dimensional inviscid and nearly dissipationless vortex dynamics through an approach we call complementary modeling. We have identified and studied physical-space processes like merger, binding, axisymmetrization-and-gradient-intensification of near-isolated regions of vorticity. We have employed a variety of algorithms and codes including pseudo-spectral, contour dynamical, and our recently introduced moment model. Through the last application, we have solved analytically an asymptotical representation of the symmetric merger problem and provided causes and conditions for merger that agree with pseudospectral and contour dynamical simulations. We have also delineated the essential parameters which control the final state of two nonidentical nearby vortices asymmetric merger. Keywords Computer simulation, Algorithms, Vorticity, Vortex dynamics, Coherent structures, Chaotic structures.

Descriptors:

• *VORTICES
• ALGORITHMS
• COHERENCE
• COMPUTERIZED SIMULATION
• CONTOURS
• DYNAMICS
• MODELS
• MOMENTS
• SIMULATION
• STRUCTURES
• INVISCID FLOW
• TWO DIMENSIONAL FLOW

Subject Categories:

• Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE