用神经算子跳过传统计算步骤,快速预测流体动力学行为
Fast-Forward Lattice Boltzmann: Learning Kinetic Behaviour with Physics-Informed Neural Operators
- 基于物理约束的神经算子直接预测长期流体演化
- 突破时间步长限制,在复杂流动中保持高精度
- 可跨网格尺度通用,适合各类流体模拟场景
格子玻尔兹曼方程(LBE)基于粒子分布函数描述复杂流动行为。尽管有效,其数值求解受碰撞核严格时间步长限制,计算成本高。本文提出一种物理信息神经算子框架,实现对大时间跨度的直接预测,无需逐步积分,从而规避碰撞核显式求解。通过引入LBE的固有矩匹配约束与分布场全局等变性,模型能捕捉底层动能系统的复杂动态。该框架具备离散化无关性,使在粗网格上训练的模型可泛化至更细网格(动能超分辨率)。同时对具体碰撞模型形式无依赖,适用于不同动力学机制的动能数据集。实验验证了在冯·卡门涡街、液丝断裂和气泡粘附等复杂流动中的鲁棒性,为动能系统建模开辟了新的数据驱动路径。
原文摘要 · Abstract (English)
The lattice Boltzmann equation (LBE), rooted in kinetic theory, provides a powerful framework for capturing complex flow behaviour by describing the evolution of single-particle distribution functions (PDFs). Despite its success, solving the LBE numerically remains computationally intensive due to strict time-step restrictions imposed by collision kernels. Here, we introduce a physics-informed neural operator framework for the LBE that enables prediction over large time horizons without step-by-step integration, effectively bypassing the need to explicitly solve the collision kernel. We incorporate intrinsic moment-matching constraints of the LBE, along with global equivariance of the full distribution field, enabling the model to capture the complex dynamics of the underlying kinetic system. Our framework is discretization-invariant, enabling models trained on coarse lattices to generalise to finer ones (kinetic super-resolution). In addition, it is agnostic to the specific form of the underlying collision model, which makes it naturally applicable across different kinetic datasets regardless of the governing dynamics. Our results demonstrate robustness across complex flow scenarios, including von Karman vortex shedding, ligament breakup, and bubble adhesion. This establishes a new data-driven pathway for modelling kinetic systems.
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