title: Padé approximation in time-domain boundary conditions of porous surfaces.
abstract: Formulation and implementation of time-domain boundary conditions (TDBCs) at the surface of a reactive porous material are made challenging by the slow decay, complexity, or noncausal nature of many commonly used models of porous materials. In this paper, approaches are described that improve computational efficiency and enforce causality. One approach involves approximating the known TDBC for the modified Zwikker-Kosten impedance model as a summation of decaying exponential functions. A second approach, which can be applied to any impedance model, involves replacing the characteristic admittance with its Padé approximation. Then, approximating fractional derivatives with decaying exponentials, a causal and recursive TDBC is formulated.
authors.affiliation: NOAA/Earth System Research Laboratory, Boulder, Colorado 80305, USA.
authors.forename: Vladimir E
authors.initials: VE
authors.lastname: Ostashev
authors.forename: Sandra L
authors.initials: SL
authors.lastname: Collier
authors.forename: D Keith
authors.initials: DK
authors.lastname: Wilson
authors.forename: David F
authors.initials: DF
authors.lastname: Aldridge
authors.forename: Neill P
authors.initials: NP
authors.lastname: Symons
authors.forename: David
authors.initials: D
authors.lastname: Marlin
mesh_terms: D000162:Acoustics; D001272:Atmosphere; D003198:Computer Simulation; D005583:Fourier Analysis; D008962:Models, Theoretical; D016062:Porosity; D011312:Pressure; D013997:Time Factors