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We develop a unified and easy to use framework to study robust fully discrete numerical methods for nonlinear degenerate diffusion equations $$ \partial_t u-\mathfrak{L}^{\sigma,\mu}[\varphi(u)]=f \quad\quad\text{in}\quad\quad…

Numerical Analysis · Mathematics 2019-06-20 Félix del Teso , Jørgen Endal , Espen R. Jakobsen

A physical-mathematical approach to anomalous diffusion may be based on fractional diffusion equations and related random walk models. The fundamental solutions of these equations can be interpreted as probability densities evolving in time…

Statistical Mechanics · Physics 2008-05-27 Rudolf Gorenflo , Francesco Mainardi

In this article we study the numerical approximation of a variable coefficient fractional diffusion equation. Using a change of variable, the variable coefficient fractional diffusion equation is transformed into a constant coefficient…

Numerical Analysis · Mathematics 2019-02-28 Xiangcheng Zheng , V. J. Ervin , Hong Wang

The advection-diffusion and wave equations are the fundamental equations governing any physical law and therefore arise in many areas of physics and astrophysics. For complex problems and geometries, only numerical simulations can give…

Computational Physics · Physics 2014-01-08 J. Pétri

A finite difference method is constructed to solve singularly perturbed convection-diffusion problems posed on smooth domains. Constraints are imposed on the data so that only regular exponential boundary layers appear in the solution. A…

Numerical Analysis · Mathematics 2021-12-23 Alan F. Hegarty , Eugene O'Riordan

This paper proposes the use of a Spectral method to simulate diffusive moisture transfer through porous materials as a Reduced-Order Model (ROM). The Spectral approach is an a priori method assuming a separated representation of the…

Computational Physics · Physics 2020-02-20 Suelen Gasparin , Julien Berger , Denys Dutykh , Nathan Mendes

In this paper, we propose high order numerical methods to solve a 2D advection diffusion equation, in the highly oscillatory regime. We use an integrator strategy that allows the construction of arbitrary high-order schemes {leading} to an…

Numerical Analysis · Mathematics 2024-11-11 Clarissa Astuto

Space fractional convection diffusion equation describes physical phenomena where particles or energy (or other physical quantities) are transferred inside a physical system due to two processes: convection and superdiffusion. In this…

Numerical Analysis · Mathematics 2014-05-20 Minghua Chen , Weihua Deng

Fractional Fokker-Planck equation plays an important role in describing anomalous dynamics. To the best of our knowledge, the existing discussions mainly focus on this kind of equation involving one diffusion operator. In this paper, we…

Numerical Analysis · Mathematics 2021-09-08 Jing Sun , Weihua Deng , Daxin Nie

Simple finite differencing of the anisotropic diffusion equation, where diffusion is only along a given direction, does not ensure that the numerically calculated heat fluxes are in the correct direction. This can lead to negative…

Instrumentation and Methods for Astrophysics · Physics 2015-05-19 Prateek Sharma , Gregory W. Hammett

Nonlinear time fractional partial differential equations are widely used in modeling and simulations. In many applications, there are high contrast changes in media properties. For solving these problems, one often uses coarse spatial grid…

Numerical Analysis · Mathematics 2022-07-13 Wenyuan Li , Anatoly Alikhanov , Yalchin Efendiev , Wing Tat Leung

A numerical method for approximating weak solutions of an aggregation equation with degenerate diffusion is introduced. The numerical method consists of a stabilized finite element method together with a mass lumping technique and an extra…

Explicit numerical finite difference schemes for partial differential equations are well known to be easy to implement but they are particularly problematic for solving equations whose solutions admit shocks, blowups and discontinuities.…

Numerical Analysis · Mathematics 2016-10-19 Christopher. N. Angstmann , Bruce I. Henry , Byron A. Jacobs , Anna V. McGann

Numerical solutions of a non-Fickian diffusion equation belonging to a hyperbolic type are presented in one space dimension. The Brownian particle modelled by this diffusion equation is subjected to a symmetric periodic potential whose…

Computational Physics · Physics 2013-02-27 Adérito Araújo , Amal K. Das , Cidália Neves , Ercília Sousa

In this paper we present in one-dimensional space a numerical solution of a partial differential equation of fractional order. This equation describes a process of anomalous diffusion. The process arises from the interactions within the…

Numerical Analysis · Mathematics 2007-05-23 Mariusz Ciesielski , Jacek Leszczynski

An unsteady problem is considered for a space-fractional diffusion equation in a bounded domain. A first-order evolutionary equation containing a fractional power of an elliptic operator of second order is studied for general boundary…

Numerical Analysis · Computer Science 2014-12-19 Petr N. Vabishchevich

In this paper, we develop an efficient numerical solver for unsteady diffusion-type partial differential equations with random coefficients. A major computational challenge in such problems lies in repeatedly handling large-scale linear…

Numerical Analysis · Mathematics 2026-01-19 Yujun Zhu , Min Li , Yulan Ning , Ju Ming

In this paper, we consider the initial boundary value problem of the two dimensional multi-term time fractional mixed diffusion and diffusion-wave equations. An alternating direction implicit (ADI) spectral method is developed based on…

Numerical Analysis · Mathematics 2018-09-03 Zeting Liu , Fawang Liu , Fanhai Zeng

We present an ``equation-free'' multiscale approach to the simulation of unsteady diffusion in a random medium. The diffusivity of the medium is modeled as a random field with short correlation length, and the governing equations are cast…

Numerical Analysis · Mathematics 2007-05-23 Dongbin Xiu , Ioannis Kevrekidis

In this paper, a diffusion-aggregation equation with delta potential is introduced. Based on the global existence and uniform estimates of solutions to the diffusion-aggregation equation, we also provide the rigorous derivation from a…

Analysis of PDEs · Mathematics 2019-12-13 Li Chen , Simone Göttlich , Stephan Knapp