Numerical solution of acoustic scattering by finite perforated elastic plates

Autor(es)

Cavalieri, A. V. G. ^[1] ; Wolf, W. R. ^[2] ; Jaworski, J. W. ^[3]

Afiliação do(s) autor(es)

^[1] Inst Tecnol Aeronaut, Div Engn Aeronaut, BR-12228900 Sao Paulo - Brazil

^[2] Univ Estadual Campinas, Fac Engn Mecan, BR-13083860 Sao Paulo - Brazil

^[3] Lehigh Univ, Dept Mech Engn & Mech, Bethlehem, PA 18015 - USA

• Tipo de documento: Artigo Científico
• Fonte: PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SC; v. 472, n. 2188 APR 1 2016.
• Citações Web of Science: 8

Resumo

We present a numerical method to compute the acoustic field scattered by finite perforated elastic plates. A boundary element method is developed to solve the Helmholtz equation subjected to boundary conditions related to the plate vibration. These boundary conditions are recast in terms of the vibration modes of the plate and its porosity, which enables a direct solution procedure. A parametric study is performed for a two-dimensional problem whereby a cantilevered perforated elastic plate scatters sound from a point quadrupole near the free edge. Both elasticity and porosity tend to diminish the scattered sound, in agreement with previous work considering semi-infinite plates. Finite elastic plates are shown to reduce acoustic scattering when excited at high Helmholtz numbers k(0) based on the plate length. However, at low k(0), finite elastic plates produce only modest reductions or, in cases related to structural resonance, an increase to the scattered sound level relative to the rigid case. Porosity, on the other hand, is shown to be more effective in reducing the radiated sound for low k(0). The combined beneficial effects of elasticity and porosity are shown to be effective in reducing the scattered sound for a broader range of k(0) for perforated elastic plates. (AU)

• Processo FAPESP: 13/03413-4 - Investigação da geração e propagação de ruído em configurações aerodinâmicas utilizando aeroacústica computacional
• Beneficiário: William Roberto Wolf
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores
• Processo FAPESP: 14/05671-3 - 20th AIAA/CEAS Aeroacoustics Conference
• Beneficiário: André Valdetaro Gomes Cavalieri
• Modalidade de apoio: Auxílio à Pesquisa - Reunião - Exterior