Physics-Informed Neural Networks for Joint Source and Parameter Estimation in Advection-Diffusion Equations

TL;DR

This paper introduces a novel physics-informed neural network approach using multiple neural networks and the neural tangent kernel to jointly estimate sources, parameters, and solutions in advection-diffusion equations from limited noisy data.

Contribution

It extends PINNs with a weighted NTK-based method for joint inverse problems involving multiple unknowns, improving efficiency and robustness.

Findings

Successfully estimated source functions and parameters in 2D and 3D experiments.

Demonstrated robustness to measurement noise.

Achieved accurate solution recovery in complex scenarios.

Abstract

Recent studies have demonstrated the success of deep learning in solving forward and inverse problems in engineering and scientific computing domains, such as physics-informed neural networks (PINNs). Source inversion problems under sparse measurements for parabolic partial differential equations (PDEs) are particularly challenging to solve using PINNs, due to their severe ill-posedness and the multiple unknowns involved including the source function and the PDE parameters. Although the neural tangent kernel (NTK) of PINNs has been widely used in forward problems involving a single neural network, its extension to inverse problems involving multiple neural networks remains less explored. In this work, we propose a weighted adaptive approach based on the NTK of PINNS including multiple separate networks representing the solution, the unknown source, and the PDE parameters. The key idea behind our methodology is to simultaneously solve the joint recovery of the solution, the source function along with the unknown parameters thereby using the underlying partial differential equation as a constraint that couples multiple unknown functional parameters, leading to more efficient use of the limited information in the measurements. We apply our method on the advection-diffusion equation and we present various 2D and 3D numerical experiments using different types of measurements data that reflect practical engineering systems. Our proposed method is successful in estimating the unknown source function, the velocity and diffusion parameters as well as recovering the solution of the equation, while remaining robust to additional noise in the measurements.