0

Full Content is available to subscribers

Subscribe/Learn More  >

An Acoustic Superposition Method for Computing Structural Radiation in Spatially Digitized Domains

[+] Author Affiliations
Brian C. Zellers, Gary H. Koopmann

Pennsylvania State University, University Park, PA

Michael L. Jonson

Pennsylvania State University, State College, PA

Paper No. IMECE2007-41313, pp. 105-121; 17 pages
doi:10.1115/IMECE2007-41313
From:
  • ASME 2007 International Mechanical Engineering Congress and Exposition
  • Volume 12: New Developments in Simulation Methods and Software for Engineering Applications
  • Seattle, Washington, USA, November 11–15, 2007
  • Conference Sponsors: ASME
  • ISBN: 0-7918-4306-8 | eISBN: 0-7918-3812-9
  • Copyright © 2007 by ASME

abstract

This paper presents a new method for computing acoustic fields of structural radiators based on a coustic s uperposition methods using m eshless, spatially d igitized d omains (ASMDD). Here the system matrices are assembled knowing only coordinate points in 3D space that describe the geometry of the radiating structure. In contrast to conventional methods, ASMDD does not require numerical, high orders of integration over elemental surfaces to populate system matrices. The system’s Green functions are computed simply between source and receiver locations at their respective points. A new derivation provides an analytical solution for coincident source and receiver points where the Green function is singular. The digital domain of ASMDD is a uniform distribution of points equidistant in the x, y, and z directions. The centroid of each activated voxel (used only as a means for visualizing the 3D surface) represents a point on the structural surface being modeled. Work in this paper exploits the inherent uniformity of neighboring points to formulate a locally determined outward-pointing, surface normal needed for acoustic radiation problems. The ability of the calculated surface normals to model the curvature of the continuous radiating surface depends on the density of the meshless grid, i.e., higher curvature requires higher grid densities. The attractiveness of the digital domain approach is its simplicity for morphing of structural shapes in optimization. Shape iterations in the digitized space reduce to a simple process of activating or deactivating selected points in a contiguous manner depending on the desired shape during an optimization. As an example, the ASMDD formulation is used to compute the modal radiation from a square plate in an infinite and cubic baffle. The ASMDD surface points are shown to blend seamlessly with the surface vibration results of the plate generated via meshless structural dynamics (M eshless L ocal P etrov G alerkin method - MLPG). This is achieved by solving the modal radiated acoustic power from the plate where the surface velocity is specified by the modal results determined by the MLPG method. The sound power calculations are in good agreement with those generated via conventional BEM codes.

Copyright © 2007 by ASME

Figures

Tables

Interactive Graphics

Video

Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In