🤖 AI Summary
Existing machine learning solvers—such as PINNs, FNOs, and DeepONets—excel on single-field PDEs but lack systematic evaluation and methodological adaptation for strongly coupled multiphysics systems governed by multi-physics PDEs. To address this gap, we introduce Multiphysics Bench, the first general-purpose benchmark dataset for strongly coupled multiphysics PDEs, comprising 12 canonical problem classes. Through rigorous evaluation, we identify a critical failure mode: mainstream methods suffer significant performance degradation due to inadequate modeling of inter-field coupling. We propose three targeted strategies—loss reweighting, gradient coordination, and cross-field information interaction—to mitigate this limitation. Our experiments deliver reproducible baselines, failure-mode analysis, and 12 actionable guidelines. This work establishes the first comprehensive benchmark and methodology framework for multiphysics scientific machine learning, bridging the gap between current solvers and real-world complex physical systems.
📝 Abstract
Solving partial differential equations (PDEs) with machine learning has recently attracted great attention, as PDEs are fundamental tools for modeling real-world systems that range from fundamental physical science to advanced engineering disciplines. Most real-world physical systems across various disciplines are actually involved in multiple coupled physical fields rather than a single field. However, previous machine learning studies mainly focused on solving single-field problems, but overlooked the importance and characteristics of multiphysics problems in real world. Multiphysics PDEs typically entail multiple strongly coupled variables, thereby introducing additional complexity and challenges, such as inter-field coupling. Both benchmarking and solving multiphysics problems with machine learning remain largely unexamined. To identify and address the emerging challenges in multiphysics problems, we mainly made three contributions in this work. First, we collect the first general multiphysics dataset, the Multiphysics Bench, that focuses on multiphysics PDE solving with machine learning. Multiphysics Bench is also the most comprehensive PDE dataset to date, featuring the broadest range of coupling types, the greatest diversity of PDE formulations, and the largest dataset scale. Second, we conduct the first systematic investigation on multiple representative learning-based PDE solvers, such as PINNs, FNO, DeepONet, and DiffusionPDE solvers, on multiphysics problems. Unfortunately, naively applying these existing solvers usually show very poor performance for solving multiphysics. Third, through extensive experiments and discussions, we report multiple insights and a bag of useful tricks for solving multiphysics with machine learning, motivating future directions in the study and simulation of complex, coupled physical systems.