Frequency-selective induction of excitation waves near sub- and supercritical Hopf bifurcation

2004 ◽  
Vol 330 (5) ◽  
pp. 350-357 ◽  
Author(s):  
Gerold Baier ◽  
Markus Müller
Keyword(s):  
Hopf Bifurcation ◽  
Supercritical Hopf Bifurcation ◽  
Frequency Selective

Pushing amplitude equations far from threshold: application to the supercritical Hopf bifurcation in the cylinder wake

2016 ◽  
Vol 48 (6) ◽  
pp. 061401 ◽  
Author(s):  
Francois Gallaire ◽  
Edouard Boujo ◽  
Vladislav Mantic-Lugo ◽  
Cristobal Arratia ◽  
Benjamin Thiria ◽  
...  
Keyword(s):  
Hopf Bifurcation ◽  
Cylinder Wake ◽  
Amplitude Equations ◽  
Supercritical Hopf Bifurcation

THE COHERENCE RESONANCE IN VAN DER POL SYSTEM INDUCED BY NOISE RECYCLING

2012 ◽  
Vol 11 (02) ◽  
pp. 1250002 ◽  
Author(s):  
X. Y. LI ◽  
J. H. YANG ◽  
X. B. LIU
Keyword(s):  
Hopf Bifurcation ◽  
Time Delay ◽  
Natural Frequency ◽  
Coherence Resonance ◽  
Van Der Pol ◽  
Input Noise ◽  
Supercritical Hopf Bifurcation ◽  
Induced Motion

The phenomenon of coherence resonance (CR) in a delayed noisy Van der Pol system with supercritical Hopf bifurcation, which is influenced by a recycled noise, is numerically studied. Different from the traditional CR theory, in this paper, the characteristics of CR is affected by the time delay in the input noise. Namely, the CR is weakened or enhanced by the time delay feedback. Moreover, we find that several characteristics of this particular system vary periodically and its period has some certain relation with the natural frequency. By using the results given by the paper, we can control the noise-induced motion by modulating the time delay in noise.

New results in rotating Hagen–Poiseuille flow

2000 ◽  
Vol 417 ◽  
pp. 103-126 ◽  
Author(s):  
D. R. BARNES ◽  
R. R. KERSWELL
Keyword(s):  
Hopf Bifurcation ◽  
Couette Flow ◽  
Poiseuille Flow ◽  
Travelling Waves ◽  
Three Dimensional ◽  
Axial Rotation ◽  
Finite Amplitude ◽  
Two Dimensional ◽  
Rotation Rates ◽  
Supercritical Hopf Bifurcation

New three-dimensional finite-amplitude travelling-wave solutions are found in rotating Hagen–Poiseuille flow (RHPF[Ωa, Ωp]) where fluid is driven by a constant pressure gradient along a pipe rotating axially at rate Ωa and at Ωp about a perpendicular diameter. For purely axial rotation (RHPF[Ωa, 0]), the two-dimensional helical waves found by Toplosky & Akylas (1988) are found to become unstable to three-dimensional travelling waves in a supercritical Hopf bifurcation. The addition of a perpendicular rotation at low axial rotation rates is found only to stabilize the system. In the absence of axial rotation, the two-dimensional steady flow solution in RHPF[0, Ωp] which connects smoothly to Hagen–Poiseuille flow as Ωp → 0 is found to be stable at all Reynolds numbers below 104. At high axial rotation rates, the superposition of a perpendicular rotation produces a ‘precessional’ instability which here is found to be a supercritical Hopf bifurcation leading directly to three-dimensional travelling waves. Owing to the supercritical nature of this primary bifurcation and the secondary bifurcation found in RHPF[Ωa, 0], no opportunity therefore exists to continue these three-dimensional finite-amplitude solutions in RHPF back to Hagen–Poiseuille flow. This then contrasts with the situation in narrow-gap Taylor–Couette flow where just such a connection exists to plane Couette flow.

Analysis of Hopf Bifurcation of Steering Wheel Shimmy of Automobile

2013 ◽  
Vol 344 ◽  
pp. 61-65
Author(s):  
Li Juan He ◽  
Yu Cun Zhou
Keyword(s):  
Nonlinear Dynamics ◽  
Hopf Bifurcation ◽  
Numerical Analysis ◽  
Limit Cycle ◽  
Critical Speed ◽  
Stable Limit Cycle ◽  
Steering Wheel ◽  
Stable Limit ◽  
Supercritical Hopf Bifurcation ◽  
Wheel Shimmy

It proves that steering wheel shimmy is a vibration of stable limit cycle occurring after Hopf bifurcation, which is elaborated by nonlinear dynamics theory, and the control objectives of shimmy are proposed according to its bifurcation properties. Numerical analysis of bifurcation characteristics has been conducted with a nonlinear shimmy model whose parameters come from a domestic automobile with independent suspension. The results indicate that when the speed reaches 49.98Km/h, supercritical Hopf bifurcation occurs to the system and stable limit cycle appears, i.e. wheels oscillate around the kingpin at the same amplitude; when the speed comes to 76.30 Km/h, Hopf bifurcation occurs again and limit cycle disappears. The bifurcation speed and amplitude of limit cycle match the shimmy speed and amplitude measured from road experiments very well, which confirms the conclusions that shimmy is a vibration of stable limit cycle occurring after Hopf bifurcation at critical speed.

MESOSCOPIC DESCRIPTION OF CHEMICAL SUPERCRITICAL HOPF BIFURCATION

2004 ◽  
Vol 14 (07) ◽  
pp. 2393-2397 ◽  
Author(s):  
QIAN SHU LI ◽  
RUI ZHU
Keyword(s):  
Hopf Bifurcation ◽  
Small Amplitude ◽  
Model System ◽  
Limit Cycle Oscillation ◽  
Hopf Bifurcation Point ◽  
Supercritical Hopf Bifurcation ◽  
New Type ◽  
Internal Signal ◽  
Cycle Oscillation ◽  
Oregonator Model

The mesoscopic dynamic behavior of the Oregonator model of the Belousov–Zhabotinsky chemical reaction is investigated as the model system experiences a supercritical Hopf bifurcation from focus to limit cycle oscillation. The study is performed by stochastically simulating the corresponding chemical master equation. Comparing the mesoscopic dynamic results with those obtained by the macroscopic dynamics, we find in the mesoscopic description a new type of oscillating state, in which large-amplitude oscillations and small-amplitude oscillations appear randomly alternately. This new state comes out spontaneously within a certain region called Hopf bifurcation range by us. In the mesoscopic description, the Hopf bifurcation point cannot be shown, being replaced by a Hopf bifurcation range. Furthermore, the applications of this new oscillating state to internal signal stochastic resonance are pointed out.

A global stability analysis of the steady and periodic cylinder wake

1994 ◽  
Vol 270 ◽  
pp. 297-330 ◽  
Author(s):  
Bernd R. Noack ◽  
Helmut Eckelmann
Keyword(s):  
Periodic Solution ◽  
Stability Analysis ◽  
Hopf Bifurcation ◽  
Three Dimensional ◽  
Reynolds Numbers ◽  
Cylinder Wake ◽  
Global Stability Analysis ◽  
Supercritical Hopf Bifurcation ◽  
Low Dimensional ◽  
Transition Scenario

A global, three-dimensional stability analysis of the steady and the periodic cylinder wake is carried out employing a low-dimensional Galerkin method. The steady flow is found to be asymptotically stable with respect to all perturbations for Re < 54. The onset of periodicity is confirmed to be a supercritical Hopf bifurcation which can be modelled by the Landau equations. The periodic solution is observed to be only neutrally stable for 54 < Re < 170. While two-dimensional perturbations of the vortex street rapidly decay, three-dimensional perturbations with long spanwise wavelengths neither grow nor decay. The periodic solution becomes unstable at Re = 170 by a perturbation with the spanwise wavelength of 1.8 diameters. This instability is shown to be a supercritical Hopf bifurcation in the spanwise coordinate and leads to a three-dimensional periodic flow. Finally the transition scenario for higher Reynolds numbers is discussed.

Sign in / Sign up

Export Citation Format

Share Document