Polymer scission in turbulent flows
Polymer scission in turbulent flows
复制标题
湍流中的聚合物断裂
DOI：
10.1017/jfm.2020.1092
复制
发表时间：
2021
影响因子：
3.7
通讯作者：
Picardo Jason R.
中科院分区：
文献类型：
--
作者：
Vincenzi Dario;Watanabe Takeshi;Ray Samriddhi Sankar;Picardo Jason R.
湍流中的聚合物会受到强烈的应变，这会导致聚合物的断裂，从而限制了湍流减阻和弹性湍流等现象的实验研究和应用。在本文中，我们研究聚合物断裂均匀各向同性湍流，通过随机建模相结合，基于高斯时间去相关的随机流，直接数值模拟（DNS）与单向（被动）和双向（主动）耦合的聚合物，建模为珠弹簧链，和流量。对于被动聚合物的第一次分裂，随机模型产生的分析预测被发现是在良好的协议与结果从DNS，为时间演变的未破碎的聚合物的分数和统计的聚合物的生存。通过具有双向耦合的DNS（活性聚合物）研究了断裂对湍流聚合物溶液动力学的影响。我们的研究结果表明，由于从拉伸聚合物的反馈动能耗散的减少是一个固有的瞬态效应，这是失去了作为聚合物打破。因此，通过中间聚合物弛豫时间使总体耗散减少最大化，对于该中间聚合物弛豫时间，聚合物显著拉伸但不会太快断裂。我们还研究了断裂后形成的聚合物片段的动力学;这些子聚合物本身可以经历随后的、重复的断裂，以产生具有一系列弛豫时间和断裂速率的聚合物的分层群体。
Polymers in a turbulent flow are subject to intense strain, which can cause their scission and thereby limit the experimental study and application of phenomena such as turbulent drag reduction and elastic turbulence. In this paper, we study polymer scission in homogeneous isotropic turbulence, through a combination of stochastic modelling, based on a Gaussian time-decorrelated random flow, and direct numerical simulations (DNS) with both one-way (passive) and two-way (active) coupling of the polymers, modelled as bead-spring chains, and the flow. For the first scission of passive polymers, the stochastic model yields analytical predictions which are found to be in good agreement with results from the DNS, for the temporal evolution of the fraction of unbroken polymers and the statistics of the survival of polymers. The impact of scission on the dynamics of a turbulent polymer solution is investigated through DNS with two-way coupling (active polymers). Our results indicate that the reduction of kinetic energy dissipation due to feedback from stretched polymers is an inherently transient effect, which is lost as the polymers break up. Thus, the overall dissipation reduction is maximized by an intermediate polymer relaxation time, for which polymers stretch significantly but without breaking too quickly. We also study the dynamics of the polymer fragments which form after scission; these daughter polymers can themselves undergo subsequent, repeated, breakups to produce a hierarchical population of polymers with a range of relaxation times and scission rates.
登录
查看更多内容
DOI：
--
发表时间：
1999
期刊：
影响因子：
--
作者：
J. H. Cifre;J. Torre
通讯作者：
J. Torre
聚合物链拉伸流动的模拟。
影响因子：
4.4
作者：
J. Cascales;J. Torre
通讯作者：
J. Torre
湍流中不可延伸的小纤维的动力学和破碎
DOI：
--
发表时间：
2019
期刊：
Philosophical Transactions of the Royal Society A
影响因子：
--
作者：
Sofía Allende;C. Henry;J. Bec
通讯作者：
J. Bec
影响因子：
56.9
作者：
Perkins, TT;Smith, DE;Chu, S
通讯作者：
Chu, S
DOI：
10.1103/physreve.81.066301
发表时间：
2010-06
期刊：
Physical review. E, Statistical, nonlinear, and soft matter physics
影响因子：
--
作者：
Takeshi Watanabe;T. Gotoh
通讯作者：
Takeshi Watanabe;T. Gotoh