论文标题
M2N:PDE求解器的网格运动网络
M2N: Mesh Movement Networks for PDE Solvers
论文作者
论文摘要
主流数值部分微分方程(PDE)求解器需要使用网格离散物理域。网格运动方法旨在通过增加解决方案无法解决的网格解决方案来提高数值解决方案的准确性,同时降低其他地方的不必要分辨率。但是,网格运动方法(例如Monge-Ampere方法)需要解决辅助方程的溶液,这可能非常昂贵,尤其是在经常适应网格时。在本文中,我们旨在为了了解我们的最佳知识,这是PDE求解器的第一个基于学习的端到端网格运动框架。基于学习的网格运动方法的关键要求是减轻网格缠结,边界一致性和对不同分辨率网格的概括。为了实现这些目标,我们将神经样条模型和图形注意网络(GAT)分别引入我们的模型。尽管基于神经间隙的模型为大变形提供了更大的灵活性,但基于GAT的模型可以处理具有更复杂形状的域,并且可以更好地执行精致的局部变形。我们验证了我们的固定和时间依赖性,线性和非线性方程的方法,以及定期和不规则形状的域。与传统的Monge-Ampere方法相比,我们的方法可以极大地加速网格适应过程,同时实现可比的数值误差降低。
Mainstream numerical Partial Differential Equation (PDE) solvers require discretizing the physical domain using a mesh. Mesh movement methods aim to improve the accuracy of the numerical solution by increasing mesh resolution where the solution is not well-resolved, whilst reducing unnecessary resolution elsewhere. However, mesh movement methods, such as the Monge-Ampere method, require the solution of auxiliary equations, which can be extremely expensive especially when the mesh is adapted frequently. In this paper, we propose to our best knowledge the first learning-based end-to-end mesh movement framework for PDE solvers. Key requirements of learning-based mesh movement methods are alleviating mesh tangling, boundary consistency, and generalization to mesh with different resolutions. To achieve these goals, we introduce the neural spline model and the graph attention network (GAT) into our models respectively. While the Neural-Spline based model provides more flexibility for large deformation, the GAT based model can handle domains with more complicated shapes and is better at performing delicate local deformation. We validate our methods on stationary and time-dependent, linear and non-linear equations, as well as regularly and irregularly shaped domains. Compared to the traditional Monge-Ampere method, our approach can greatly accelerate the mesh adaptation process, whilst achieving comparable numerical error reduction.