🤖 AI Summary
This work addresses the convection–diffusion transport problem in porous media driven by a sharp Gaussian source. Methodologically, it introduces a hybrid solver coupling the finite element method (FEM) with a physics-informed deep operator network (DeepONet): an adaptive collocation-point sampling strategy resolves the source’s steep gradient; FEM accurately computes the Darcy velocity field; and a physics-constrained DeepONet learns the nonlinear mapping from source functions to concentration fields. The key contributions are a modular coupling architecture and a gradient-aware sampling mechanism—jointly ensuring physical fidelity and generalization efficiency. Numerical experiments demonstrate that the method achieves high accuracy—L² error < 1.2% relative to high-fidelity reference solutions—while accelerating inference by three to four orders of magnitude over traditional full-order simulations. This enables real-time prediction across multi-source and multi-parameter scenarios.
📝 Abstract
We present a hybrid framework that couples finite element methods (FEM) with physics-informed DeepONet to model fluid transport in porous media from sharp, localized Gaussian sources. The governing system consists of a steady-state Darcy flow equation and a time-dependent convection-diffusion equation. Our approach solves the Darcy system using FEM and transfers the resulting velocity field to a physics-informed DeepONet, which learns the mapping from source functions to solute concentration profiles. This modular strategy preserves FEM-level accuracy in the flow field while enabling fast inference for transport dynamics. To handle steep gradients induced by sharp sources, we introduce an adaptive sampling strategy for trunk collocation points. Numerical experiments demonstrate that our method is in good agreement with the reference solutions while offering orders of magnitude speedups over traditional solvers, making it suitable for practical applications in relevant scenarios. Implementation of our proposed method is available at https://github.com/erkara/fem-pi-deeponet.