Results 51 to 60 of about 252,123 (184)

Study on Band Gap and Sound Insulation Characteristics of an Adjustable Helmholtz Resonator

Applied Sciences, 2022
To solve the problem of low-frequency noise in the environment, a Helmholtz-type phononic crystal with adjustable cavity structure and labyrinth tubes was designed.
Donghai Han, Guangjun Zhang, Jing-Bo Zhao, Hong Yao, Hong Liu   +4 more
semanticscholar   +1 more source

Stabilization of acoustic modes using Helmholtz and Quarter-Wave resonators tuned at exceptional points

, 2018
Acoustic dampers are efficient and cost-effective means for suppressing thermoacoustic instabilities in combustion chambers. However, their design and the choice of their purging air mass flow is a challenging task, when one aims at ensuring ...
Bourquard, Claire, Noiray, Nicolas
core   +1 more source

Influence of the neck shape for Helmholtz resonators [PDF]

The Journal of the Acoustical Society of America, 2017
The resonance of a Helmholtz resonator is studied with a focus on the influence of the neck shape. This is done using a homogenization approach developed for an array of resonators, and the resonance of an array is discussed when compared to that of a single resonator.
Mercier, Jean-François, Marigo, Jean-Jacques, Maurel, Agnès   +2 more
openaire   +4 more sources

Numerical optimizing noise damping performances of Helmholtz resonators with a rigid baffle implemented at neck in presence of a grazing flow

Journal of Low Frequency Noise, Vibration and Active Control, 2022
As an applicable noise attenuator, Helmholtz resonator is mainly used to dampen acoustic noise at low- and medium-frequency ranges. It is typically implemented in combustion-engines and gas turbines to dampen thermoacoustic instabilities. However, it has
Weiwei Wu, Yiheng Guan
doaj   +1 more source

Acoustic characterization of Hofstadter butterfly with resonant scatterers

, 2002
We are interested in the experimental characterization of the Hofstadter butterfly by means of acoustical waves. The transmission of an acoustic pulse through an array of 60 variable and resonant scatterers periodically distribued along a waveguide is ...
Dubos V., Ensslin K., Flandrin P., Gabor D., Levine H., O Richoux, Pierce A. D., Richoux O., Schlösser T., V Pagneux, Zwikker C.   +10 more
core   +2 more sources

RESEARCH OF THE RESONANCE PROPERTIES OF HELMHOLTZ RESONATORS

ScienceRise, 2020
The object of research. Process of oscillation of the Helmholtz resonators. Investigated problem. Differences between some formulas for the calculation of the resonant frequency of the Helmholtz resonator and the most accurate of them were established.
Yuliia Kopytko, Vitaliy Zaets, Sergey Naida, Vitaliy Didkovskyi, Anastasiia Damarad   +4 more
openaire   +2 more sources

Numerical analyses of acoustic vibrational resonance in a Helmholtz resonator

Nonlinear dynamics
In this study, the numerical analyses of a system, which describes the motion of air particles in the cavity of a Helmholtz resonator (HR), excited by a sound wave, was conducted. The low-frequency (LF) signal in the acoustic field is amplitude-modulated
K. A. Omoteso, O. Ozioko, O. Bagdasar, T. Roy-Layinde, U. Diala   +4 more
semanticscholar   +1 more source

Origin of Negative Density and Modulus in Acoustic Metamaterials

, 2016
This paper provides a review and fundamental physical interpretation for the effective densities and moduli of acoustic metamaterials. We introduce the terminology of hidden force and hidden source of volume: the effective density or modulus is negative ...
Lee, Sam Hyeon, Wright, Oliver B.
core   +1 more source

Excited resonance widths for Helmholtz resonators with straight neck [PDF]

Journal of Spectral Theory, 2020
We consider resonances associated with excited eigenvalues of the cavity of a general Helmholtz resonator with straight neck. Under the assumption that the neck stays away from the nodal set of the corresponding eigenstate, we generalise the optimal exponential lower bound on the width of the resonance, that we have obtained in a previous paper for the
Duyckaerts T., Grigis A., Martinez A.
openaire   +4 more sources

Photoacoustic trace gas detection of OCS using a 2.45 mL Helmholtz resonator and a 4823.3 nm ICL light source

Photoacoustics
A miniaturized photoacoustic spectroscopy-based gas sensor is proposed for the purpose of detecting sub-ppm-level carbonyl sulfide (OCS) using a tunable mid-infrared interband cascade laser (ICL) and a Helmholtz photoacoustic cell.
Zijian Gao, Lei Li, Minghui Liu, Shen Tian, Mingyang Feng, Yingying Qiao, Chongxin Shan   +6 more
semanticscholar   +1 more source