The deep learning boom motivates researchers and practitioners of computational fluid dynamics eager to integrate the two areas.The PINN (physics-informed neural network) method is one such attempt. While most reports in the literature show positive outcomes of applying the PINN method, our experiments with it stifled such optimism. This work presents our not-so-successful story of using PINN to solve two fundamental flow problems: 2D Taylor-Green vortex at $Re = 100$ and 2D cylinder flow at $Re = 200$. The PINN method solved the 2D Taylor-Green vortex problem with acceptable results, and we used this flow as an accuracy and performance benchmark. About 32 hours of training were required for the PINN method's accuracy to match the accuracy of a $16 \times 16$ finite-difference simulation, which took less than 20 seconds. The 2D cylinder flow, on the other hand, did not even result in a physical solution. The PINN method behaved like a steady-flow solver and did not capture the vortex shedding phenomenon. By sharing our experience, we would like to emphasize that the PINN method is still a work-in-progress. More work is needed to make PINN feasible for real-world problems.

本文介绍了用 PINN（受物理启发的神经网络）作为传统求解器替代品解决 Navier-Stokes 方程的实验，并使用 2D 的 Taylor-Green 涡旋和圆柱流问题作为实验数据。结果表明，尽管 PINN 方法在 Taylor-Green 问题上表现良好，但在圆柱流问题上未能产生物理解。这表明 PINN 方法在无已知数据的情况下求解流动问题仍有待进一步探究。

物理信息神经网络在流体仿真中的经验报告：陷阱与挫折