Results 211 to 220 of about 546,551 (249)

An equivalent source method for acoustic problems with thermoviscous effects

The Journal of the Acoustical Society of America
This paper presents an equivalent source method (ESM) for analyzing sound propagation in small-scale acoustic structures with thermoviscous effects. The formulations that describe the thermal, viscous, and acoustic modes for thermoviscous acoustic problems are introduced.
Meng-Hui Liang, Chang-Jun Zheng, Yong-Bin Zhang, Shuai Wang, Chuan-Xing Bi   +4 more
openaire   +2 more sources

A sparse equivalent source method for near-field acoustic holography

The Journal of the Acoustical Society of America, 2017
This study examines a near-field acoustic holography method consisting of a sparse formulation of the equivalent source method, based on the compressive sensing (CS) framework. The method, denoted Compressive–Equivalent Source Method (C-ESM), encourages spatially sparse solutions (based on the superposition of few waves) that are accurate when the ...
Efren, Fernandez-Grande, Angeliki, Xenaki, Peter, Gerstoft   +2 more
openaire   +2 more sources

Underwater measurement of source level in waveguides using equivalent source method

The Journal of the Acoustical Society of America, 2017
This paper develops a method to evaluate the source level of the underwater structure in shallow water waveguides. This method requires the measurement of the pressure on a closed surface surrounding the underwater structure and the knowledge of waveguide parameters, or the measurement of the pressure and the velocity on a closed surface surrounding ...
Tengjiao He, Shiqi Mo, Erzheng Fang
openaire   +1 more source

Incorporating non-linear lumped elements in FDTD: the equivalent source method

International Journal of Numerical Modelling: Electronic Networks, Devices and Fields, 1999
Summary: A new approach is presented for modelling three-dimensional lumped elements in the finite-difference time-domain (FDTD) solution of Maxwell's equations. The finite-difference equations for the lumped element's circuit behaviour are derived to produce discrete relationships between the device's terminal currents and voltages.
Mix, Jason, Dixon, Jonathan, Popovic, Zoya, Piket-May, Melinda   +3 more
openaire   +2 more sources

An Augmented Source Method for the Application of Nodal Equivalence Theory

Nuclear Science and Engineering, 1995
The application of nodal equivalence theory (NET) in multigroup diffusion theory has required the use of ``discontinuity factors`` (DFs) to account for the homogenization errors that are inherent in all coarse-mesh nodal methods. Traditionally, DFs have been applied directly to the nodal matrix equations as multipliers to the group constants.
C. J. Hah, T. J. Downar
openaire   +1 more source

Equivalent Source Method and Boundary Element Method for Calculating Combustion Noise

Acta Acustica united with Acustica, 2008
In this paper, the application of the Equivalent Source Method (ESM) and the acoustical Boundary Element Method (BEM) for the prediction of the noise generated by an open diffusion flame is investigated. These acoustical methods have been coupled with a Large Eddy Simulation (LES) of the turbulent flow, which simulates the flow and combustion processes
Rafael Piscoya, Haike Brick, Martin Ochmann, Peter Költzsch   +3 more
openaire   +1 more source

AN EQUIVALENT SOURCE METHOD FOR CALCULATION OF THE SOUND RADIATED FROM AIRCRAFT ENGINES

Journal of Sound and Vibration, 1997
A theoretical/numerical method is described to predict the radiated sound field of a propfan model by using the pressure fluctuations measured in the exit plane (near field). The prediction scheme is based on the equivalent source method, which is extended to include the effects of the mean flow conditions of an aircraft engine.
openaire   +3 more sources

Nearfield acoustic holography based on the equivalent source method

Science in China Series E, 2005
On the basis of the nearfield acoustic holography (NAH) based on the distributed source boundary point method (DSBPM), a novel NAH based on the equivalent source method (ESM) is proposed. The theoretical model of the proposed method is established at first. And then, the error sensitivity and the reconstruction problems of a multi-source acoustic field
openaire   +1 more source

Sound Source Identification in a Rectangular Duct Based on the Equivalent Source Method

2021 4th International Conference on Information Communication and Signal Processing (ICICSP), 2021
Xiao-Zheng Zhang, Yu Lu, Chuan-Xing Bi, Yong-Bin Zhang   +3 more
openaire   +1 more source

Formulation of Boundary Integral Equations by the Equivalent Source Method

1992
The boundary element method is basically the matricization of a boundary integral equation which can be derived several ways. The two most popular methods are (1) use of a Green’s function in Green’s theorem, and (2) use of equivalent surface sources plus the uniqueness theorem.
openaire   +1 more source