scholarly journals High-amplitude sound propagation in acoustic transmission-line metamaterial

2021 ◽  
Vol 118 (10) ◽  
pp. 104102
Author(s):  
Jiangyi Zhang ◽  
Vicente Romero-García ◽  
Georgios Theocharis ◽  
Olivier Richoux ◽  
Vassos Achilleos ◽  
...  
Keyword(s):  
Transmission Line ◽  
Sound Propagation ◽  
High Amplitude ◽  
Acoustic Transmission

High Amplitude Sound Propagation at Low Frequencies in a Flow Duct Lined With Resonators: A Time Domain Solution

1988 ◽  
Vol 110 (4) ◽  
pp. 545-551 ◽  
Author(s):  
A. Cummings ◽  
I.-J. Chang
Keyword(s):  
Time Domain ◽  
Internal Combustion Engines ◽  
Sound Propagation ◽  
Sound Field ◽  
High Amplitude ◽  
Combustion Engines ◽  
Low Frequencies ◽  
The Time Domain ◽  
Flow Duct ◽  
Good Agreement

A quasi one-dimensional analysis of sound transmission in a flow duct lined with an array of nonlinear resonators is described. The solution to the equations describing the sound field and the hydrodynamic flow in the neighborhood of the resonator orifices is performed numerically in the time domain, with the object of properly accounting for the nonlinear interaction between the acoustic field and the resonators. Experimental data are compared to numerical computations in the time domain and generally very good agreement is noted. The method described here may readily be extended for use in the design of exhaust mufflers for internal combustion engines.

scholarly journals Simulation of Normal Incidence Sound Absorption Coefficients of Perforated Panels With/Without Glass Wool by Transmission Line Parameters in a Two-Port Network

2016 ◽  
Vol 44 ◽  
pp. 123-130
Author(s):  
Takayoshi Nakai
Keyword(s):  
Transmission Line ◽  
Input Impedance ◽  
Thermal Conduction ◽  
Sound Absorption ◽  
Sound Propagation ◽  
Viscous Friction ◽  
Normal Incidence ◽  
Glass Wool ◽  
Absorption Coefficients ◽  
Transfer Function Method

This paper describes simulation of normal incidence sound absorption coefficients of perforated panels by transmission line parameters in a two-port network. Maa and Sakagami have investigated micro perforated panels, MPP. But their theories can treat only near 1 % perforation rates of perforated panels with back cavities. If sound propagates as a plane wave, sound propagation can be represented as transmission line parameters in a two-port network. Perforated panels, back cavities, and glass wool absorption materials are represented as matrix of transmission line parameters, respectively. Transmission line parameters of a perforated panel with a back cavity are calculated as multiplication of their matrices. An input impedance can be calculated from the transmission line parameters. A normal incident absorption coefficient is calculated from the input impedance. Holes of the perforated panels have losses of viscous friction and thermal conduction at their walls. Simulations are done in the condition of 0.25 mm to 5 mm diameters of holes, 0.25 % to 25 % perforation rates, 0.5 mm to 5 mm thickness of the perforated panels with back cavities in which there are or are not glass wool absorption materials. The results of these simulations are good agreements with the results of our measurements by transfer function method except in the condition of more than 1 mm diameter of holes.

Evolution of the wave steepening factor for high-amplitude sound propagation

2013 ◽  
Vol 134 (5) ◽  
pp. 3981-3981
Author(s):  
Michael B. Muhlestein ◽  
Kent L. Gee ◽  
Tracianne B. Nielsen ◽  
Derek C. Thomas
Keyword(s):  
Sound Propagation ◽  
High Amplitude

Evolution of the derivative skewness for high-amplitude sound propagation

2014 ◽  
Vol 135 (4) ◽  
pp. 2381-2382
Author(s):  
Brent O. Reichman ◽  
Michael B. Muhlestein ◽  
Kent L. Gee ◽  
Tracianne B. Neilsen ◽  
Derek C. Thomas
Keyword(s):  
Sound Propagation ◽  
High Amplitude

scholarly journals A comprehensive discrete-time computer modeling of acoustic Transmission Line loudspeakers

2011 ◽  
Vol 72 (10) ◽  
pp. 742-753
Author(s):  
José Escolano ◽  
Basilio Pueo ◽  
José J. Lopez
Keyword(s):  
Transmission Line ◽  
Computer Modeling ◽  
Discrete Time ◽  
Acoustic Transmission

Time-domain impedance formulation for transmission line matrix modelling of outdoor sound propagation

2011 ◽  
Vol 330 (26) ◽  
pp. 6467-6481 ◽  
Author(s):  
Gwenaël Guillaume ◽  
Judicaël Picaut ◽  
Guillaume Dutilleux ◽  
Benoît Gauvreau
Keyword(s):  
Transmission Line ◽  
Time Domain ◽  
Sound Propagation ◽  
Transmission Line Matrix ◽  
Matrix Modelling

scholarly journals Pneumothorax effects on pulmonary acoustic transmission

2015 ◽  
Vol 119 (3) ◽  
pp. 250-257 ◽  
Author(s):  
Hansen A. Mansy ◽  
Robert A. Balk ◽  
William H. Warren ◽  
Thomas J. Royston ◽  
Zoujun Dai ◽  
...  
Keyword(s):  
Sound Propagation ◽  
Human Subjects ◽  
Sound Transmission ◽  
Transmission Measurement ◽  
Sound Waves ◽  
Acoustic Transmission ◽  
Lung Collapse ◽  
Breath Sounds ◽  
Before And After ◽  
Threatening Condition

Pneumothorax (PTX) is an abnormal accumulation of air between the lung and the chest wall. It is a relatively common and potentially life-threatening condition encountered in patients who are critically ill or have experienced trauma. Auscultatory signs of PTX include decreased breath sounds during the physical examination. The objective of this exploratory study was to investigate the changes in sound transmission in the thorax due to PTX in humans. Nineteen human subjects who underwent video-assisted thoracic surgery, during which lung collapse is a normal part of the surgery, participated in the study. After subjects were intubated and mechanically ventilated, sounds were introduced into their airways via an endotracheal tube. Sounds were then measured over the chest surface before and after lung collapse. PTX caused small changes in acoustic transmission for frequencies below 400 Hz. A larger decrease in sound transmission was observed from 400 to 600 Hz, possibly due to the stronger acoustic transmission blocking of the pleural air. At frequencies above 1 kHz, the sound waves became weaker and so did their changes with PTX. The study elucidated some of the possible mechanisms of sound propagation changes with PTX. Sound transmission measurement was able to distinguish between baseline and PTX states in this small patient group. Future studies are needed to evaluate this technique in a wider population.

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