Papers Published

  1. Danilov, P.V. and Bliss, D.B., Homogenization of periodic structures using wavenumber filtering for efficient numerical solution, 8th International Congress on Acoustics (2004), pp. 4 pp. - .
    (last updated on 2007/04/09)

    Vehicle structures, such as fuselages and hulls, have spatially periodic discontinuities such as braces, ribs, and attachments. The structural motion, and the acoustic radiation, scattering, and the interior sound field are of interest. Calculating the motion of fluid-loaded structures is a complicated task because of the high complexity and a disparity of length scales requiring high numerical resolution. Discontinuities cause the structural response to occur in a broad spectrum of spatial wavenumbers, and to exhibit stop-band and pass-band behavior. Structural discontinuities broaden the spatial wavenumber spectrum, causing both supersonic (radiating) and subsonic (nonradiating) waves. A new analysis method called local-global homogenization (LGH) is used to predict directly the low wavenumber smooth response of periodic structures in a selfcontained manner. The low wavenumber part of the response is most efficiently coupled to the acoustic field, since low wavenumbers correspond to supersonic phase speeds. In the LGH reformulation, the equivalent smooth global problem is governed by an infinite order operator that must be truncated for numerical solution. The numerical implementation is described and sample calculations are presented

    acoustic field;acoustic wave scattering;periodic structures;structural acoustics;subsonic flow;supersonic flow;