A discontinuous Galerkin method for nonlinear parabolic equations and gradient flow problems with interaction potentials

• Published in: Journal of computational physics Vol. 352; no. C; pp. 76 - 104
• Main Authors: Sun, Zheng, Carrillo, José A., Shu, Chi-Wang
• Format: Journal Article
• Language: English
• Published: Cambridge Elsevier Inc 01.01.2018; Elsevier Science Ltd; Elsevier
• Subjects: Accuracy; Computational physics; Density distribution; Discontinuous Galerkin method; Entropy; Entropy of solution; Entropy–entropy dissipation relationship; Galerkin method; Gradient flow; Mathematical models; Mathematics; MATHEMATICS AND COMPUTING; Nonlinear equations; Nonlinear parabolic equation; Parabolas; Partial differential equations; Positivity-preserving; Time dependence; Entropy–entropy dissipation relationship; Discontinuous Galerkin method; Positivity-preserving; Gradient flow; Nonlinear parabolic equation
• ISSN: 0021-9991; 1090-2716
• DOI: 10.1016/j.jcp.2017.09.050

We consider a class of time-dependent second order partial differential equations governed by a decaying entropy. The solution usually corresponds to a density distribution, hence positivity (non-negativity) is expected. This class of problems covers important cases such as Fokker–Planck type equations and aggregation models, which have been studied intensively in the past decades. In this paper, we design a high order discontinuous Galerkin method for such problems. If the interaction potential is not involved, or the interaction is defined by a smooth kernel, our semi-discrete scheme admits an entropy inequality on the discrete level. Furthermore, by applying the positivity-preserving limiter, our fully discretized scheme produces non-negative solutions for all cases under a time step constraint. Our method also applies to two dimensional problems on Cartesian meshes. Numerical examples are given to confirm the high order accuracy for smooth test cases and to demonstrate the effectiveness for preserving long time asymptotics.