Provider: ingentaconnect
Database: ingentaconnect
Content: application/x-research-info-systems
TY - ABST
AU - Wilson, D. Keith
AU - Collier, Sandra L.
AU - Ostashev, Vladimir E.
AU - Aldridge, David F.
AU - Symons, Neill P.
AU - Marlin, David H.
TI - Time-Domain Modeling of the Acoustic Impedance of Porous Surfaces
JO - Acta Acustica united with Acustica
PY - 2006-11-01T00:00:00///
VL - 92
IS - 6
SP - 965
EP - 975
N2 - A time-domain boundary condition (TDBC) for acoustic reflections from a rigid-frame porous material is derived. The TDBC is the time-domain counterpart of the familiar, linear, frequency-dependent surface impedance for locally reacting surfaces. Although the TDBC is developed from a rather simple, two-parameter phenomenological model, it is shown to apply to a broad range of frequencies and to agree closely with predictions from more sophisticated models that do not have readily derivable time-domain formulas. The TDBC gives the pressure as the sum of two terms involving the particle velocity normal to the surface of the material: one term is directly proportional to the particle velocity at the present time, whereas the other involves a convolution of the particle velocity with a slowly decaying response function. Numerical implementation of the TDBC is discussed and illustrated with example finite-difference, time-domain calculations involving propagation over a porous ground surface.
UR - http://www.ingentaconnect.com/content/dav/aaua/2006/00000092/00000006/art00016
ER -