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Physical Sciences and Mathematics Commons

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Brigham Young University

Astrophysics and Astronomy

Acoustic intensity

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Full-Text Articles in Physical Sciences and Mathematics

Use Of Phase And Amplitude Gradient Estimation For Acoustic Source Characterization And Localization, Joseph Scott Lawrence Jul 2018

Use Of Phase And Amplitude Gradient Estimation For Acoustic Source Characterization And Localization, Joseph Scott Lawrence

Theses and Dissertations

Energy-based acoustic quantities provide vital information about acoustic fields and the characterization of acoustic sources. Recently, the phase and amplitude gradient estimator (PAGE) method has been developed to reduce error and extend bandwidth of energy-based quantity estimates. To inform uses and applications of the method, analytical and experimental characterizations of the method are presented. Analytical PAGE method bias errors are compared with those of traditional estimation for two- and three-microphone one-dimensional probes. For a monopole field when phase unwrapping is possible, zero bias error is achieved for active intensity using three-microphone PAGE and for specific acoustic impedance using two-microphone PAGE. …


Energy Quantity Estimation In Radiated Acoustic Fields, Eric B. Whiting Sep 2016

Energy Quantity Estimation In Radiated Acoustic Fields, Eric B. Whiting

Theses and Dissertations

Energy quantities, which are calculated from pressure and particle velocity, yield a great deal of information about acoustic fields. Errors in pressure or particle velocity estimation lead to bias errors the estimation of energy quantities. The bias errors arise from different probe configurations and processing methods. Two processing methods are examined: the traditional method and the recently developed Phase and Amplitude Gradient Estimation (PAGE) method. These two methods are compared to investigate how each estimates pressure and particle velocity and the subsequent bias errors in a plane wave, standing wave, and spherical spreading wave field. Analytical expressions are derived for …


Performance Of Phase And Amplitude Gradient Estimator Method For Calculating Energy Quantities In A Plane-Wave Tube Environment, Daxton A. Hawks Aug 2016

Performance Of Phase And Amplitude Gradient Estimator Method For Calculating Energy Quantities In A Plane-Wave Tube Environment, Daxton A. Hawks

Student Works

Acoustic intensity, energy densities, and impedance are useful quantities when considering sound fields. Calculating these energy quantities relies on measurements of acoustic pressure and particle velocity. Pressure and particle velocity can be directly measured, but direct measurements of particle velocity are difficult to make, and are normally inaccurate. A more common and effective way to find particle velocity is to estimate it using pressure measurements from two closely-spaced microphones. The traditional way of estimating particle velocity is severely limited by frequency. The PAGE method, developed at Brigham Young University, extends the frequency bandwidth at which accurate estimations can be made. …


Investigation Of A New Method Of Estimating Acoustic Intensity And Its Application To Rocket Noise, Benjamin Young Christensen Jul 2014

Investigation Of A New Method Of Estimating Acoustic Intensity And Its Application To Rocket Noise, Benjamin Young Christensen

Theses and Dissertations

An alternative pressure-sensor based method for estimating the acoustic intensity, the phase and amplitude gradient estimation (PAGE) method, is presented. This method is similar to the finite-difference p-p (FD) method, in which the intensity is estimated from pressure measurements made using an array of closely spaced microphones. The PAGE method uses the same hardware as the FD method, but does not suffer from the frequency-dependent bias inherent to the FD method. Detailed derivations of the new method and the traditional FD method are presented. Both methods are then compared using two acoustic fields: a plane wave and a three monopole …