Graduate School in Nonlinear Science
MIDIT OFD CATS
Modelling, Nonlinear Dynamics Optics and Fluid Dynamics Chaos and Turbulence Studies
and Irreversible Thermodynamics Risø National Laboratory Niels Bohr Institute and
Technical University of Denmark Building 128 Department of Chemistry
Building 321 P.O. Box 49 University of Copenhagen
DK-2800 Lyngby DK-4000 Roskilde DK-2100 Copenhagen Ø
Denmark Denmark Denmark
NONLINEAR SYSTEM IDENTIFICATION IN FLUID-ELASTIC DYNAMICS
Francis C. Moon
Cornell University,
USA
MIDIT-seminar 501
Friday, November 16, 2001, 14.00 h
at IMM, Bldg. 305, Room 053, DTU
Abstract:
This lecture will describe methods for identifying nonlinear
bifurcation models for problems with autonomous generation of limit
cycle dynamics from experimental data. Two techniques will be
described; one based on the classical harmonic balance method and
least squares ideas, and the other based on center manifold theory
and normal forms ideas from nonlinear dynamical systems. These
methods have been applied to a nonlinear electrical circuit as well
as self-excited motions in fluid-structure dynamics. The unique
difficulty that is addressed in these methods is how to capture the
subcritical bifurcation structure of the limit cycle behavior. This
difficulty is solved by using constraints from center manifold
analysis on the least squares problem.