论文标题
深层随机涡流方法,用于模拟和推断Navier-Stokes方程
Deep Random Vortex Method for Simulation and Inference of Navier-Stokes Equations
论文作者
论文摘要
Navier-Stokes方程是描述液体和空气等流体运动的重要部分微分方程。由于Navier-Stokes方程的重要性,有效的数值方案的发展对科学和工程师都很重要。最近,随着AI技术的开发,已经设计了几种方法,以整合深层神经网络,以模拟和推断由不可压缩的Navier-Stokes方程所控制的流体动力学,这些动态可以加速以无网状和不同的方式加速模拟或推断过程。在本文中,我们指出,现有的深度Navier-Stokes知情方法的能力仅限于处理非平滑或分数方程,这在现实中是两种关键情况。为此,我们提出了\ emph {deep Random Vortex方法}(DRVM),该方法将神经网络与随机涡流动力学系统相当于Navier-Stokes方程。具体而言,随机涡流动力学激发了训练神经网络的基于蒙特卡洛的损失函数,从而避免通过自动差异来计算衍生物。因此,DRVM不仅可以有效地求解涉及粗糙路径,非差异初始条件和分数操作员的Navier-Stokes方程,还可以继承基于深度学习的求解器的无网格和可区分的好处。我们对凯奇问题,参数求解器学习以及2-D和3-D不可压缩的Navier-Stokes方程进行了实验。所提出的方法为Navier-Stokes方程的仿真和推断取得了准确的结果。特别是对于包括奇异初始条件的情况,DRVM明显胜过现有的Pinn方法。
Navier-Stokes equations are significant partial differential equations that describe the motion of fluids such as liquids and air. Due to the importance of Navier-Stokes equations, the development on efficient numerical schemes is important for both science and engineer. Recently, with the development of AI techniques, several approaches have been designed to integrate deep neural networks in simulating and inferring the fluid dynamics governed by incompressible Navier-Stokes equations, which can accelerate the simulation or inferring process in a mesh-free and differentiable way. In this paper, we point out that the capability of existing deep Navier-Stokes informed methods is limited to handle non-smooth or fractional equations, which are two critical situations in reality. To this end, we propose the \emph{Deep Random Vortex Method} (DRVM), which combines the neural network with a random vortex dynamics system equivalent to the Navier-Stokes equation. Specifically, the random vortex dynamics motivates a Monte Carlo based loss function for training the neural network, which avoids the calculation of derivatives through auto-differentiation. Therefore, DRVM not only can efficiently solve Navier-Stokes equations involving rough path, non-differentiable initial conditions and fractional operators, but also inherits the mesh-free and differentiable benefits of the deep-learning-based solver. We conduct experiments on the Cauchy problem, parametric solver learning, and the inverse problem of both 2-d and 3-d incompressible Navier-Stokes equations. The proposed method achieves accurate results for simulation and inference of Navier-Stokes equations. Especially for the cases that include singular initial conditions, DRVM significantly outperforms existing PINN method.