On The Use of a Diffusion Equation Model for Sound Energy Flow Prediction in Acoustically Coupled Spaces
Y. Jing, and N. Xiang
Rensselaer Polytechnic Institute, Troy, NY, USA
This paper studies sound energy flows through an aperture across two coupled spaces using a diffusion equation model. The so-called double sloped sound energy decay is believed to be caused by the sound energy exchange through the aperture coupling the two rooms. The room diffusion equation is first solved by COMSOL, then the time dependent energy flow is visualized via COMSOL arrow plotting, ...
Acoustic Attenuation Performance Of Helicoidal Resonator Due To Distance Change From Different Cross-Sectional Elements Of Cylindrical Duct
Poznań University of Technology, Poznań, Poland
This work presents acoustic attenuation performance of helicoidal resonator due to distance change from different cross-sectional elements of cylindrical duct. The helicoidal resonator properties are described mainly in in infinite long cylindrical duct. For practical applications it is important to know the limits of use of this solution. This paper describes how the helicoidal resonator should ...
R. C. Thiagarajan
ATOA Technologies, Bangalore, India.
Multiphysics acoustics is increasingly used to design products to meet sound, ultrasound and infrasound and other structural, thermal, electromagnetic requirements. In this paper, Multiphysics Acoustical applications such as digital stethoscope, glazing products and acoustical metamaterials are detailed. Stethoscopes are in use for more than 200 years for medical diagnostics, especially for ...
K. McIlhany, and R. Malek-Madani
Physics Department, United States Naval Academy, Annapolis, MD, USA
Mathematics Department, United States Naval Academy, Annapolis, MD, USA
In 1966, mathematician Mark Kac proposed the question "Can One Hear the Shape of a Drum?" in an article for American Mathematical Monthly. In attempting to resolve the Chesapeake Bay from an eigenfunctional approach, a one-to-one mapping of this famous problem has been identified. The quote above will re-write to "Can One Hear the Shape of a Drum from Multiple Point-Sampled Spectra?". This ...
C. J. Morgan , S. R. Fischbach ,
 Jacobs ESSSA Group, NASA Marshall Space Flight Center, Huntsville, AL, USA
This study evaluates the effect of injector resistance on the mode shapes and complex eigenfrequencies of an injector/combustion chamber system by defining a high Mach-flow, potential flow form of the convective wave equation in the Coefficient Form PDE Mathematics interface. Background steady-state flow conditions are determined through a NASA Marshall Space Flight Center in-house fluid ...
D. M. Forrester ,
 Loughborough University, Loughborough, United Kingdom
When the particles in a colloid come close to each other, multiple scattering in ultrasonic beams is no longer negligible and crowded particle effects emerge. The presence of each particle affects the scattering of all others, leading to coupling effects. We investigate the interaction of a range of sizes of particles, arranged periodically or randomly (in medium to high ultrasonic frequency ...
R. Lardat ,
 Thales Underwater Systems, Sophia Antipolis, France
The simulation of a large acoustic cylindrical antenna made of numerous identical transducers is very often out of reach in terms of computational cost. Therefore the usual design procedure consist in optimizing the transducer standing alone, either in free field arrangement or sitting on a hard baffle. Once the antenna is produced, one can very often see problems arising on the antenna response ...
Beam Structure As an Acoustic Wave Sensor: A Study of the Effect of Sensor Design on Its Sensitivity to Noise
F. Akasheh, A. Biddle, W.S. Shepard Jr., and B.B.B. Zhang
Tuskegee University, Tuskegee, AL, USA
University of Alabama, Tuscaloosa, AL, USA
The detection and identification of the location of a sound source is commonly done using arrays of microphones. A recent new alternative approach has been proposed which involves the use of continuous structures, such as beams or plates, as acoustic wave sensors. The sound wave impinging on the surface of the structure causes it to vibrate and the measured surface displacements can then be used ...