Related Experiment Video
Updated: Mar 30, 2026
08:19
Induction of Microstreaming by Nonspherical Bubble Oscillations in an Acoustic Levitation System
Published on: May 9, 2021
2.9K
Coherence resonance in a thermoacoustic system
Lipika Kabiraj1, Richard Steinert1, Aditya Saurabh1
1Chair of Fluid Dynamics, Hermann-Föttinger-Institut (HFI), Technische Universität Berlin, D-10623 Berlin, Germany.
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|November 14, 2015
Summary
Noise influences thermoacoustic systems near a Hopf bifurcation. Coherence resonance acts as a precursor, enhancing system stability before oscillations emerge.
Area of Science:
- Physics
- Nonlinear Dynamics
- Fluid Dynamics
Background:
- Thermoacoustic systems are prone to self-excited oscillations.
- Hopf bifurcations describe the transition from stable states to oscillatory behavior.
- Noise can significantly alter the dynamics of nonlinear systems.
Purpose of the Study:
- To experimentally investigate noise-induced dynamics in a thermoacoustic system.
- To identify precursors to a subcritical Hopf bifurcation.
- To understand the role of noise in the onset of thermoacoustic oscillations.
Main Methods:
- Experimental setup of a prototypical thermoacoustic system.
- Analysis of pressure oscillations in the combustor.
- Measurement of heat release rate fluctuations.
- Systematic variation of noise levels.
Main Results:
- Observed precursors to the Hopf bifurcation with increasing noise.
- Identified coherence resonance as the mechanism behind these precursors.
- Characterized the noise-induced dynamics prior to the bistable regime.
Conclusions:
- Noise can induce predictable dynamics in thermoacoustic systems.
- Coherence resonance plays a crucial role in the transition to oscillations.
- Understanding these precursors is vital for controlling thermoacoustic instabilities.
Related Concept Videos
01:14Sound Waves: Resonance
3.7K
Resonance is produced depending on the boundary conditions imposed on a wave. Resonance can be produced in a string under tension with symmetrical boundary conditions (i.e., has a node at each end). A node is defined as a fixed point where the string does not move. The symmetrical boundary conditions result in some frequencies resonating and producing standing waves, while other frequencies interfere destructively. Sound waves can resonate in a hollow tube, and the frequencies of the sound...
3.7K
01:28Standing Waves in a Cavity
1.6K
A household microwave and lasers are examples of standing electromagnetic waves in a cavity. When two conducting metal plates are placed parallel at the nodal planes, it creates a cavity where standing waves are formed. The cavity between the two planes is analogous to a stretched string held at the points x = 0 and x = L. Here, the distance 'L' between the two planes must be an integer multiple of half of the wavelength. The wavelengths that satisfy this condition are given by:
1.6K
01:19Concept of Resonance and its Characteristics
6.9K
If a driven oscillator needs to resonate at a specific frequency, then very light damping is required. An example of light damping includes playing piano strings and many other musical instruments. Conversely, to achieve small-amplitude oscillations as in a car's suspension system, heavy damping is required. Heavy damping reduces the amplitude, but the tradeoff is that the system responds at more frequencies. Speed bumps and gravel roads prove that even a car's suspension system is not...
6.9K
01:26Resonance in an AC Circuit
2.7K
The property of an inductor makes it resist any change in the current passing through it, while the property of a capacitor is to build up the charge across its terminals. Hence, if an inductor and capacitor are connected in series, they have opposite effects on the relative phase between current and voltage. The current through the circuit undergoes forced oscillation at the frequency of the source. The resistance term in an R-L-C circuit acts as a damping term because power is dissipated...
2.7K
01:23Parallel Resonance
732
The parallel RLC circuit is an arrangement where the resistor (R), inductor (L), and capacitor (C) are all connected to the same nodes and, as a result, share the same voltage across them. The parallel RLC circuit is analyzed in terms of admittance (Y), which reflects the ease with which current can flow. The admittance is given by:
732
01:12Double Resonance Techniques: Overview
850
Double resonance techniques in Nuclear Magnetic Resonance (NMR) spectroscopy involve the simultaneous application of two different frequencies or radiofrequency pulses to manipulate and observe two distinct nuclear spins. One important application of double resonance is spin decoupling, which selectively suppresses coupling with one type of nucleus while observing the NMR signal from another nucleus, simplifying the spectrum and enhancing resolution.
Spin decoupling is usually achieved by...
Spin decoupling is usually achieved by...
850