🤖 AI Summary
This work addresses the critical inverse problem of reconstructing shocks, discontinuities, and rarefaction waves in compressible flows from sparse observations. We propose GraphGPS, a physics-enhanced graph neural network. Methodologically, it introduces a novel shock-aware message aggregation mechanism and enforces unidirectional information propagation constraints; on sparse graphs, it jointly incorporates positional encoding and physics-informed message passing to ensure fidelity, efficiency, and stability. Ablation studies validate the necessity of synergistically combining local message passing with global contextual modeling. Evaluated on 3D Riemann problem reconstruction, GraphGPS significantly outperforms state-of-the-art machine learning baselines: it achieves markedly improved shock resolution, accelerates training convergence, and maintains full reconstruction accuracy without degradation.
📝 Abstract
In compressible fluid flow, reconstructing shocks, discontinuities, rarefactions, and their interactions from sparse measurements is an important inverse problem with practical applications. Moreover, physics-informed machine learning has recently become an increasingly popular approach for performing reconstructions tasks. In this work we explore a machine learning recipe, known as GraphGPS, for reconstructing canonical compressible flows known as 3D Riemann problems from sparse observations, in a physics-informed manner. The GraphGPS framework combines the benefits of positional encodings, local message-passing of graphs, and global contextual awareness, and we explore the latter two components through an ablation study. Furthermore, we modify the aggregation step of message-passing such that it is aware of shocks and discontinuities, resulting in sharper reconstructions of these features. Additionally, we modify message-passing such that information flows strictly from known nodes only, which results in computational savings, better training convergence, and no degradation of reconstruction accuracy. We also show that the GraphGPS framework outperforms numerous machine learning benchmarks.