WIAS Preprint No. 3074, (2023)

On collocation points for physics-informed neural networks applied to convection-dominated convection-diffusion problems



Authors

  • Frerichs-Mihov, Derk
    ORCID: 0000-0002-4474-5042
  • Zainelabdeen, Marwa
  • John, Volker
    ORCID: 0000-0002-2711-4409

2020 Mathematics Subject Classification

  • 65N99 68T07

Keywords

  • Convection-diffusion problems, convection-dominated regime, hard-constrained physics-informed neural networks, layer-adapted collocation points

DOI

10.20347/WIAS.PREPRINT.3074

Abstract

In recent years physics-informed neural networks (PINNs) for approximating the solution to (initial-)boundary value problems gained a lot of interest. PINNs are trained to minimize several residuals of the problem in collocation points. In this work we tackle convection-dominated convection-diffusion problems, whose solutions usually possess layers, which are small regions where the solution has a steep gradient. Inspired by classical Shishkin meshes, we compare hard- constrained PINNs trained with layer-adapted collocation points with ones trained with equispaced and uniformly randomly chosen points. We observe that layer-adapted points work the best for a problem with an interior layer and the worst for a problem with boundary layers. For both problems at most acceptable solutions can be obtained with PINNs.

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