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 ...
University Paris 13 - Math. dpt.
This note is devoted to a domain decomposition method solving the Helmholtz equation in the frequency domain. We need to perform this global computation as a sequence of local computations, each computation being performed on a single subdomain, without any knowledge of the geometry and meshing of the other subdomains. This is useful when the global geometry is too big to be stored in a single ...
COMSOL Multiphysics® Software for Simulation of Surface Response to Excitation Method for Manufacturing Process Performance Monitoring
H. Fekrmandi, N. Miniello, R. Kiflemariam, I. Nur Tansel
Mechanical & Materials Engineering Department, Florida International University, Miami, FL, USA
In this study, COMSOL Multiphysics® software was used to simulate the surface response to excitation method (SuRE). An aluminum beam with a piezoelectric element bonded is modeled using the COMSOL Acoustics Module. A frequency domain sweep study was performed to simulate the sweep sign generation. The frequency spectrum of the structure is monitored through a frequency range of (20kHz-400kHz). A ...
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 ...
J. Ratnieks, A. Jakovics, and J. Klavins
University of Latvia
Although we know the physics inside a media where the sound waves propagate, determination of material\'s or structure\'s sound reduction index is not an easy task. The lack of good engineering solutions proves the point. The only reliable way to calculate the sound reduction index is to carry out an experiment.Therefore, the aim of this study is to develop a mathematical model that can ...
R. Jiang, L. Mei, X. Liu, H. Li, Q. Zhang
Department of Electrical Engineering, Materials Research Institute, Pennsylvania State University, University Park, PA, USA
Department of Technical Services, China Oilfield Services Limited, Yanshan, Hebei, China
Logging-while-drilling (LWD) acoustic transducers provide real-time data about the geologic and geophysical properties of the borehole that ensure safety margins and optimize completion. It is important to understand what causes the different resonance modes in the transmitter and obtain relevant acoustic response information to assist new designs and field applications of the transmitter. COMSOL ...
A. Ravi, R. Krishna, J. Christen
Arizona State University, Tempe, AZ, USA
Capacitive MEMS sensors offer high spatial resolution, sensitivity and good frequency response. In this paper, we present a circular membrane capacitive MEMS device that finds use both as capacitive micromachined ultrasonic transducer (CMUT) and pressure sensor. The MEMS device is first designed and simulated to work as a CMUT operating at about 5 MHz frequency. The device can also function as a ...
An Improved Loudspeaker Frequency Response by Using a Structure of Rigid Absorptive Panel in a Vented Cabinet
Community Light & Sound Inc., Chester, PA, USA
When placing a loudspeaker in a cabinet, standing waves inside the cabinet affect the frequency response with ripples. This peaks and dips due to pressure cancellation inside the cabinet have an effect on the diaphragm and generating sound out from the vents. If it was in a condition of total absorption of the sound waves at the back of the diaphragm, the transducer would otherwise have a much ...
Investigation of Mean-Flow Effects on Tubular Combustion Chamber Thermoacoustics Using a Burner Transfer Matrix Approach
A. Andreini, B. Facchini, A. Innocenti, D. Pampaloni
University of Florence, Florence, Italy
The paper presents a methodology to account for local mean-flow effects on thermo-acoustic instabilities to improve typical calculations performed under the zero-Mach number assumption. A 3D FEM model of a simplified combustor is solved with COMSOL Multiphysics® Pressure Acoustics interface. The Helmholtz equation is used to model the combustor and the classical k-τ model for the Flame Transfer ...
D. Groulx, A. Bharath, S. Campbell
Department of Mechanical Engineering, Dalhousie University, Halifax, NS, Canada
The field of underwater acoustics research is constantly growing with the ongoing improvement of acoustic measuring techniques. An acoustic hydrophone receiver is a passive listening device which is widely used in biological research and sonar technology. The hydrophone however suffers from turbulence generated noise created by its presence in ever faster flow. This work aims to analyze the ...