论文标题
使用人工扩散率在数值上保存弹性
Conserving elastic turbulence numerically using artificial diffusivity
论文作者
论文摘要
为了模拟弹性湍流，在粘弹性主导的情况下，数值求解器引入了人造应力扩散术语，以处理随之而来的陡峭聚合物应力梯度。最近已显示[Gupta＆Vincenzi，J。Fluid Mech。 870，405-418（2019）; Dzanic，来自＆Sauret，J。FluidMech。 937，A31（2022）]引入对模拟有害影响的非物理伪像。在这封信中，我们建议人工扩散仅限于应力梯度陡峭而不是寻求零扩散率极限的区域。通过细胞强迫和四圈磨机问题，我们证明了这种修饰的人工扩散性没有非物理的人工制品，从而可以保留弹性湍流的所有特征。发现结果符合直接模拟的符合，从而将人工扩散率从定性量表降低到定量量表，而仅需要数值分辨率的一部分。
To simulate elastic turbulence, where viscoelasticity dominates, numerical solvers introduce an artificial stress diffusivity term to handle the steep polymer stress gradients that ensue. This has recently been shown [Gupta & Vincenzi, J. Fluid Mech. 870, 405-418 (2019); Dzanic, From & Sauret, J. Fluid Mech. 937, A31 (2022)] to introduce unphysical artifacts with a detrimental impact on simulations. In this Letter, we propose that artificial diffusion is limited to regions where stress gradients are steep instead of seeking the zero-diffusivity limit. Through the cellular forcing and four-roll mill problem, we demonstrate that this modified artificial diffusivity is devoid of unphysical artifacts, allowing all features of elastic turbulence to be retained. Results are found to conform with direct simulations, reducing the impact of artificial diffusivity from a qualitative scale to a quantitative scale while only requiring a fraction of the numerical resolution.
