论文标题
粘弹性流的三种数值稳定技术的比较：涡流脱落的圆柱体后面
Comparison of three numerical stabilization techniques of viscoelastic flows: vortex shedding behind a confined cylinder
论文作者
论文摘要
在这项研究中，基于有限体积方法的OpenFOAM平台用于研究经过圆柱体的二维粘弹性流。选择聚合物分子的有界伸长的FENE-P模型被选择以描述聚合物溶液的弹性本质关系。考虑了L = 10、50、100和200的最大分子链长度，描述了聚合物溶液的分子构象特性。为了改善粘弹性流仿真的数值不稳定性，评估了三种不同的方法，即传统方法（TD），以添加人工粘度，对数重建方法（log）和平方根量张量方法（SQRT）。结果表明，人工粘度对较小的分子链长度的模拟精度有很小的影响（L = 10）。但是，对于长分子链长度（例如L = 100和L = 200），人工耗散的添加往往高估了阻力，这表明需要特殊谨慎以将人工耗散纳入模拟中。此外，对数重建方法显示出强大的网格依赖性特征，这可能会产生非物理结果。
In this study, the OpenFOAM platform, based on the finite volume method, is applied to investigate the two-dimensional viscoelastic flow past a circular cylinder. The FENE-P model, which considers the bounded elongation of polymer molecules, is chosen to describe the elastic constitutive relationship of the polymer solution. The maximum molecular chain lengths of L = 10, 50, 100, and 200 are considered, which describe the molecular conformation characteristics of the polymer solution. To improve the numerical instability of the viscoelastic flow simulation, three different methods, i.e., the traditional method (Td) with the addition of artificial viscosity, the logarithmic reconstruction method (Log), and the square root tensor method (Sqrt), are evaluated. The results show that the artificial viscosity has a little effect on the accuracy for the simulation with a small molecular chain length (L = 10). However, for long molecular chain lengths such as L = 100 and L = 200, the addition of artificial dissipation tends to overestimate the drag, which indicates that special caution is needed to incorporate the artificial dissipation in the simulation. Moreover, the logarithmic reconstruction method shows a strong grid-dependent characteristics, which may produce unphysical results.
