Combining linear and nonlinear diffusion

In this paper we study a generalized porous medium equation where the diffusion rate, say m(x) —spatially heterogeneous—, is assumed to be linear, m = 1, on a piece of the support domain, Ω1, and slow nonlinear, m(x) > 1, in its complement, Ωm := Ω \ Ω¯1. Most precisely, we characterize the exist...

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Detalles Bibliográficos
Autores: Delgado Delgado, Manuel, López Gómez, Julián, Suárez Fernández, Antonio
Tipo de recurso: artículo
Estado:Versión enviada para evaluación y publicación
Fecha de publicación:2004
País:España
Institución:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/49513
Acceso en línea:http://hdl.handle.net/11441/49513
https://doi.org/10.1515/ans-2004-0303
Access Level:acceso abierto
Palabra clave:Nonlinear diffusion
Spatial heterogeneities
From linear to nonlinear diffusion
Descripción
Sumario:In this paper we study a generalized porous medium equation where the diffusion rate, say m(x) —spatially heterogeneous—, is assumed to be linear, m = 1, on a piece of the support domain, Ω1, and slow nonlinear, m(x) > 1, in its complement, Ωm := Ω \ Ω¯1. Most precisely, we characterize the existence of positive solutions and construct the corresponding global bifurcation diagram as one of the parameters of the model changes, showing that a continuous transition occurs between the diagrams of the completely linear case (Ω = Ω1) and of the completely nonlinear case (Ωm = Ω). As a result, the effect of a localized slow diffusion rate with varying support is completely characterized. Our analysis is imperative in order to design porous media multi-components systems with changing diffusion rates.