论文标题
非线性流变性的冰川建模的差异神经网络方法
A variational neural network approach for glacier modelling with nonlinear rheology
论文作者
论文摘要
在本文中,我们提出了一种无网格的方法来解决完整的Stokes方程,该方程模拟了冰川运动的非线性流变学。我们的方法是受[12]中提出的深里兹方法的启发。我们首先将非牛顿冰流模型的解决方案提出到具有边界约束的变分积分的最小化器中。然后,通过深层神经网络近似溶液,该网络的损失函数是变异的积分和来自混合边界条件的软约束。我们的方法不需要引入网格网格或基础函数来评估损失函数,而只需要统一的域和边界采样器。为了解决现实缩放中的不稳定性,我们将网络的输入重新归一化,并平衡每个单个边界的正则化因子。最后,我们通过几个数值实验说明了我们的方法的性能,包括具有分析解决方案的2D模型,具有真实缩放的Arolla Glacier模型和具有周期性边界条件的3D模型。数值结果表明,我们提出的方法有效地解决了非线性流变学冰川建模引起的非牛顿力学。
In this paper, we propose a mesh-free method to solve full stokes equation which models the glacier movement with nonlinear rheology. Our approach is inspired by the Deep-Ritz method proposed in [12]. We first formulate the solution of non-Newtonian ice flow model into the minimizer of a variational integral with boundary constraints. The solution is then approximated by a deep neural network whose loss function is the variational integral plus soft constraint from the mixed boundary conditions. Instead of introducing mesh grids or basis functions to evaluate the loss function, our method only requires uniform samplers of the domain and boundaries. To address instability in real-world scaling, we re-normalize the input of the network at the first layer and balance the regularizing factors for each individual boundary. Finally, we illustrate the performance of our method by several numerical experiments, including a 2D model with analytical solution, Arolla glacier model with real scaling and a 3D model with periodic boundary conditions. Numerical results show that our proposed method is efficient in solving the non-Newtonian mechanics arising from glacier modeling with nonlinear rheology.