000013183 001__ 13183
000013183 005__ 20161114160330.0
000013183 04107 $$aeng
000013183 046__ $$k2009-06-22
000013183 100__ $$aPopescu C., A.
000013183 24500 $$aThe secondary bifurcation of a noisy aeroelastic model

000013183 24630 $$n2.$$pComputational Methods in Structural Dynamics and Earhquake Engineering
000013183 260__ $$bNational Technical University of Athens, 2009
000013183 506__ $$arestricted
000013183 520__ $$2eng$$aIn this paper we study numerically the stochastic phenomenological bifurcations of a two-degree-of-freedom noisy aeroelastic system oscillating in pitch and plunge, with a cubic non-linearity in pitch. In addition to a Hopf bifurcation, the deterministic aeroelastic model has also secondary bifurcations characterized by jumps in the amplitude and the frequency of the limit cycle oscillations. Here we study the stochastic phenomenological P-bifurcations corresponding to the deterministic secondary bifurcation. The study of the phenomenological bifurcations concerns the qualitative changes of the density of the stationary distribution associated with the system, i.e of the time independent solution of the corresponding Fokker-Planck equation. Understanding the secondary bifurcation is important because some aircrafts are operated beyond the flutter speed (e.g. the F-16), and for some systems the secondary bifurcation may occur for flow velocities not very much larger than the flutter velocity. A stochastic analysis in this case is useful for validating the mathematical model and for studying the uncertainties in the limit cycle oscillations.

000013183 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000013183 653__ $$asecondary bifurcation, stochastic phenomenological bifurcation, non-linear dynamical system, stochastic differential equation Abstract. In this paper we study numerically the stochastic phenomenological bifurcations of a two-degree-of-freedom noisy aeroelastic system oscillating in pitch and plunge, with a cubic non-linearity in pitch. In addition to a Hopf bifurcation, the deterministic aeroelastic model has also secondary bifurcations characterized by jumps in the amplitude and the frequency of the limit cycle oscillations. Here we study the stochastic phenomenological P-bifurcations corresponding to the deterministic secondary bifurcation. The study of the phenomenological bifurcations concerns the qualitative changes of the density of the stationary distribution associated with the system, i.e of the time independent solution of the corresponding Fokker-Planck equation. Understanding the secondary bifurcation is important because some aircrafts are operated beyond the flutter speed (e.g. the F-16), and for some systems the secondary bifurcation may occur for flow velocities not very much larger than the flutter velocity. A stochastic analysis in this case is useful for validating the mathematical model and for studying the uncertainties in the limit cycle oscillations.

000013183 7112_ $$aCOMPDYN 2009 - 2nd International Thematic Conference$$cIsland of Rhodes (GR)$$d2009-06-22 / 2009-06-24$$gCOMPDYN2009
000013183 720__ $$aPopescu C., A.
000013183 8560_ $$ffischerc@itam.cas.cz
000013183 8564_ $$s1333844$$uhttps://invenio.itam.cas.cz/record/13183/files/CD245.pdf$$yOriginal version of the author's contribution as presented on CD, section: Uncertainty analysis in structural dynamics and earthquake engineering - i.
000013183 962__ $$r13074
000013183 980__ $$aPAPER