Computationally resolving turbulence remains a central challenge in fluid dynamics due to its multi-scale interactions. Fully resolving large-scale turbulence through direct numerical simulation (DNS) is computationally prohibitive, motivating data-driven machine learning alternatives. In this work, we propose EddyFormer, a Transformer-based spectral-element (SEM) architecture for large-scale turbulence simulation that combines the accuracy of spectral methods with the scalability of the attention mechanism. We introduce an SEM tokenization that decomposes the flow into grid-scale and subgrid-scale components, enabling capture of both local and global features. We create a new three-dimensional isotropic turbulence dataset and train EddyFormer to achieves DNS-level accuracy at 256^3 resolution, providing a 30x speedup over DNS. When applied to unseen domains up to 4x larger than in training, EddyFormer preserves accuracy on physics-invariant metrics-energy spectra, correlation functions, and structure functions-showing domain generalization. On The Well benchmark suite of diverse turbulent flows, EddyFormer resolves cases where prior ML models fail to converge, accurately reproducing complex dynamics across a wide range of physical conditions.
翻译:计算解析湍流因其多尺度相互作用特性,仍是流体动力学中的核心挑战。通过直接数值模拟(DNS)完全解析大尺度湍流在计算上不可行,这推动了数据驱动的机器学习替代方法的发展。本研究提出EddyFormer,一种基于Transformer的谱元(SEM)架构,用于大规模湍流模拟,结合了谱方法的精度与注意力机制的可扩展性。我们引入一种SEM标记化方法,将流场分解为网格尺度与亚网格尺度分量,从而能够同时捕捉局部与全局特征。我们创建了一个新的三维各向同性湍流数据集,并训练EddyFormer在256^3分辨率下达到DNS级别的精度,相比DNS实现了30倍的加速。当应用于训练域尺寸4倍大的未见域时,EddyFormer在物理不变量指标——能量谱、相关函数和结构函数上保持了精度,展现了领域泛化能力。在包含多样化湍流场景的The Well基准测试套件中,EddyFormer解决了先前机器学习模型无法收敛的案例,准确复现了广泛物理条件下的复杂动力学行为。