On the Well-Posedness Problem of the Anisotropic Porous Medium Equation with a Variable Diffusion Coefficient

On the Well-Posedness Problem of the Anisotropic Porous Medium Equation with a Variable Diffusion Coefficient

Year:    2024

Author:    Huashui Zhan

Journal of Partial Differential Equations, Vol. 37 (2024), Iss. 2 : pp. 135–149

Abstract

The initial-boundary value problem of an anisotropic porous medium equation $$u_t=\sum^N_{i=1}\frac{\partial}{\partial x_i}(a(x,t)|u|^{\alpha_i}u_{x_i})+\sum^N_{i=1}\frac{\partial f_i(u,x,t)}{\partial x_i}$$ is studied. Compared with the usual porous medium equation, there are two different characteristics in this equation. One lies in its anisotropic property, another one is that there is a nonnegative variable diffusion coefficient $a(x,t)$ additionally. Since $a(x,t)$ may be degenerate on the parabolic boundary $∂Ω×(0,T),$ instead of the boundedness of the gradient $|∇u|$ for the usual porous medium, we can only show that $∇u∈ L^∞(0,T;L^2_{ {\rm loc}}(Ω)).$ Based on this property, the partial boundary value conditions matching up with the anisotropic porous medium equation are discovered and two stability theorems of weak solutions can be proved naturally.

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Journal Article Details

Publisher Name:    Global Science Press

Language:    English

DOI:    https://doi.org/10.4208/jpde.v37.n2.2

Journal of Partial Differential Equations, Vol. 37 (2024), Iss. 2 : pp. 135–149

Published online:    2024-01

AMS Subject Headings:   

Copyright:    COPYRIGHT: © Global Science Press

Pages:    15

Keywords:    Anisotropic porous medium equation variable diffusion coefficient stability partial boundary condition.

Author Details

Huashui Zhan