论文标题
一个浅层物理信息的神经网络,用于求解表面上的部分微分方程
A shallow physics-informed neural network for solving partial differential equations on surfaces
论文作者
论文摘要
在本文中,我们引入了一个浅(一个隐藏的)物理信息神经网络,用于求解静态和不断发展的表面的部分微分方程。对于静态表面情况,借助水平设定功能,可以轻松计算表面差分表达式中使用的表面正常和平均曲率。因此,我们没有施加文献中使用的正常扩展约束,而是以传统的笛卡尔差异操作员的形式编写表面差分运算符,并直接将其直接在损失函数中使用。我们通过在复杂的静态表面上求解拉普拉斯 - 贝特拉米方程和表面扩散方程来对本方法进行一系列性能研究。由于隐藏层中仅使用了适量的神经元,我们就能获得令人满意的预测结果。然后,我们扩展了目前的方法,以在不断发展的表面上以给定速度求解对流扩散方程。为了跟踪表面,我们还引入了一个规定的隐藏层来强制表面的拓扑结构,并使用网络来学习表面和规定的拓扑之间的同构。所提出的网络结构旨在跟踪表面并同时求解方程。同样,数值结果表现出与静态情况相当的精度。作为应用,我们在剪切流下模拟了液滴表面上的表面活性剂转运,并获得一些物理上合理的结果。
In this paper, we introduce a shallow (one-hidden-layer) physics-informed neural network for solving partial differential equations on static and evolving surfaces. For the static surface case, with the aid of level set function, the surface normal and mean curvature used in the surface differential expressions can be computed easily. So instead of imposing the normal extension constraints used in literature, we write the surface differential operators in the form of traditional Cartesian differential operators and use them in the loss function directly. We perform a series of performance study for the present methodology by solving Laplace-Beltrami equation and surface diffusion equation on complex static surfaces. With just a moderate number of neurons used in the hidden layer, we are able to attain satisfactory prediction results. Then we extend the present methodology to solve the advection-diffusion equation on an evolving surface with given velocity. To track the surface, we additionally introduce a prescribed hidden layer to enforce the topological structure of the surface and use the network to learn the homeomorphism between the surface and the prescribed topology. The proposed network structure is designed to track the surface and solve the equation simultaneously. Again, the numerical results show comparable accuracy as the static cases. As an application, we simulate the surfactant transport on the droplet surface under shear flow and obtain some physically plausible results.