Physics-informed convolutional neural networks for fluid flow through porous media
Summary
A neural-network-based framework for predicting pore-scale velocity fields in porous media is presented, utilizing a convolutional encoder-decoder (U-Net) architecture with skip connections. The method incorporates a custom loss function that enforces physical consistency, including terms for incompressibility, no-flow conditions within solids, periodicity constraints, and agreement with the global tortuosity index. The ResNet-101 architecture demonstrated superior performance, achieving a velocity RMSE of 5.1e-03 and a tortuosity R^2 of 0.983. The model exhibits strong generalization capabilities across variations in obstacle geometry, boundary conditions (e.g., pipe-like flows), and porosities within the training range of 0.70 to 0.95, and even to real Li-O2 electrode microstructures. Furthermore, using the network's predictions to initialize Lattice-Boltzmann Method (LBM) simulations significantly accelerated convergence in over 90% of cases, reducing iterations by a median of 50%. Inference time is 5 ms on GPU, substantially faster than LBM's 560 ms on CPU.
Key takeaway
For fluid dynamics researchers or engineers simulating porous media flow, you should consider integrating physics-informed convolutional neural networks. This approach significantly accelerates Lattice-Boltzmann Method (LBM) simulations by providing warm starts, reducing convergence time by a median of 50% in over 90% of cases. You can achieve high accuracy in pore-scale velocity predictions and macroscopic properties like tortuosity and permeability, even for out-of-distribution geometries, using a ResNet-101 backbone and a custom multi-term loss function.
Key insights
Physics-informed CNNs accurately predict fluid flow in porous media, significantly accelerating traditional LBM simulations.
Principles
- Custom loss functions enhance physical consistency in neural network predictions.
- Architectural complexity doesn't always improve accuracy for fixed-grid flow mapping.
- Generalization to out-of-distribution data is possible with physics-informed training.
Method
A U-Net encoder-decoder with skip connections predicts pore-scale velocity from binary geometry. A custom loss function combines velocity MSE with penalties for incompressibility, no-flow in solids, periodicity, and tortuosity matching.
In practice
- Initialize LBM simulations with CNN predictions for 50% faster convergence.
- Apply physics-informed loss to improve model generalization for fluid dynamics.
- Use ResNet-101 for high accuracy in pore-scale velocity field prediction.
Topics
- Physics-informed Neural Networks
- Pore-scale Fluid Flow
- Porous Media Simulation
- Lattice Boltzmann Method
- U-Net Architecture
- Model Generalization
Code references
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Editorial summary, takeaway, and curation by AIssential. Original article published by cs.LG updates on arXiv.org.