Elastic turbulence in two-dimensional cross-slot viscoelastic flows
Elastic turbulence in two-dimensional cross-slot viscoelastic flows
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DOI：
10.1209/0295-5075/129/24002
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发表时间：
2020-01-01
期刊：
影响因子：
1.8
通讯作者：
Berti, S.
中科院分区：
文献类型：
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作者：
Canossi, D. O.;Mompean, G.;Berti, S.
我们使用 Oldroyd-B 模型的数值模拟报告了在跨槽几何形状没有惯性的情况下二维聚合物溶液的不规则不稳定流动的证据。通过探索随时间变化的流动与流体弹性和聚合物浓度的关系，我们发现接近不稳定阈值的周期性行为以及较大弹性下更复杂的流动，与实验结果一致。对于足够高的弹性，我们获得指向弹性湍流的动力学，速度波动的时间谱显示指数在-3和-2之间的幂律衰减，并且速度波动的概率密度函数微弱地偏离高斯性，而高非高斯尾部表征了局部加速度的概率密度函数。版权所有 (C) EPLA，2020。
We report evidence of irregular unsteady flow of two-dimensional polymer solutions in the absence of inertia in cross-slot geometry using numerical simulations of Oldroyd-B model. By exploring the transition to time-dependent flow vs. both the fluid elasticity and the polymer concentration, we find a periodic behaviour close to the instability threshold and more complex flows at larger elasticity, in agreement with experimental findings. For high enough elasticity we obtain dynamics pointing to elastic turbulence, with temporal spectra of velocity fluctuations showing a power-law decay, of exponent between -3 and -2, and probability density functions of velocity fluctuations that weakly deviate from Gaussianity while high non-Gaussian tails characterise those of local accelerations. Copyright (C) EPLA, 2020.