Energy based boundary element method for broadband high frequency sound fields

The prediction of the spatial mean-square pressure distribution within enclosed high-frequency broadband sound fields is computationally intensive if determined on a frequency-by-frequency basis. Recently an energy-intensity boundary element method (EIBEM) has been formally developed. This method employs uncorrelated broadband directional energy sources to expeditiously predict such pressure distributions. The source directivity accounts for local correlation effects and specular reflection. The method is applicable to high modal density fields, but not restricted to the usual low-absorption, diffuse, and quasi-uniform assumptions. The approach can accommodate fully specular reflection, or any combination of diffuse and specular reflection. This boundary element method differs from the classical version in that element size is large compared to an acoustic wavelength and equations are not solved on a frequency-by-frequency basis. In the earlier EIBEM, the source strength and directivity associated with the energy sources, distributed over enclosure boundaries, were determined in an iterative manner and the directivity was limited to three terms of a Fourier expansion. Here, the original method is improved by eliminating the iteration and allowing for an unlimited number of terms in the Fourier expansion of the directivity function. For verification, the improved EIBEM is compared to experimental measurements and exact analytical solutions; excellent agreement is obtained.

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Development of Noise and Vibration Prediction Software in Medium-to-High Frequency Ranges Using Power Flow Boundary Element Method

10.4271/2003-01-1458 ◽

2003 ◽

Cited By ~ 1

Author(s):

Ho-Won Lee ◽

Do-Hyun Park ◽

Suk-Yoon Hong

Keyword(s):

Boundary Element Method ◽

Boundary Element ◽

High Frequency ◽

Power Flow ◽

Noise And Vibration ◽

Flow Boundary ◽

Vibration Prediction ◽

Element Method

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Energy Flow Boundary Element Method for Vibration Analysis of One and Two Dimension Structures

Shock and Vibration ◽

10.1155/2008/607379 ◽

2008 ◽

Vol 15 (1) ◽

pp. 33-50 ◽

Cited By ~ 7

Author(s):

Ho-Won Lee ◽

Suk-Yoon Hong ◽

Do-Hyun Park ◽

Hyun-Wung Kwon

Keyword(s):

Boundary Element Method ◽

Boundary Element ◽

High Frequency ◽

Energy Flow ◽

Vibration Analysis ◽

Thin Plates ◽

Two Dimensional ◽

Flow Boundary ◽

Energy Equations ◽

Element Method

In this paper, Energy Flow Boundary Element Method (EFBEM) was developed to predict the vibration behavior of one- and two-dimensional structures in the medium-to-high frequency ranges. Free Space Green functions used in the method were obtained from EFA energy equations. Direct and indirect EFBEMs were formulated for both one- and two-dimensional cases, and numerically applied to predict the energy density and intensity distributions of simple Euler-Bernoulli beams, single rectangular thin plates, and L-shaped thin plates vibrating in the medium-to-high frequency ranges. The results from these methods were compared with the EFA solutions to verify the EFBEM.

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Prediction of Acoustical Behavior in Cavities Using an Indirect Boundary Element Method

Journal of Vibration and Acoustics ◽

10.1115/1.3269390 ◽

1987 ◽

Vol 109 (1) ◽

pp. 22-28 ◽

Cited By ~ 15

Author(s):

C. R. Kipp ◽

R. J. Bernhard

Keyword(s):

Boundary Condition ◽

Boundary Element Method ◽

Boundary Element ◽

Point Sources ◽

Cavity Pressure ◽

Impedance Boundary ◽

Indirect Boundary Element Method ◽

Sound Fields ◽

Pressure Distributions ◽

Element Method

An indirect boundary element method is developed to predict sound fields in acoustical cavities. An isoparametric quadratic boundary element is utilized. The formulations of pressure, velocity and/or impedance boundary conditions are developed and incorporated into the method. The capability to include acoustic point sources within the cavity is also implemented. The method is applied to the prediction of sound fields in spherical and rectangular cavities. All three boundary condition types are verified. Cases having a point source within the cavity domain are also studied. Numerically determined cavity pressure distributions and responses are presented. The numerical results correlate well with available analytical results.

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