Elastically induced turbulence in Taylor–Couette flow: direct numerical simulation and mechanistic insight
Elastically induced turbulence in Taylor–Couette flow: direct numerical simulation and mechanistic insight
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DOI：
10.1017/jfm.2013.544
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发表时间：
2013-11
影响因子：
3.7
通讯作者：
Nansheng Liu;B. Khomami
中科院分区：
文献类型：
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作者：
Nansheng Liu;B. Khomami
摘要弹性诱导湍流的直接数值模拟（DNS）对致力于发展第一性原理模型和模拟的研究人员提出了巨大的挑战，这些模型和模拟可以忠实地预测聚合物流动的复杂时空动力学。为此，DNS的弹性诱导湍流状态的泰勒-库埃特（TC）流在这里报道的目的是铺平了道路，这类新的流动的机械理解。具体地说，DNS不仅忠实地再现了弹性诱导湍流的关键特征，即在最小的时间和空间尺度上对流体运动的实质性激发，而且还首次证明了在惯性-弹性湍流状态的差距中存在三个不同的流动区域：（i）流体惯性在一些实施例中，壁区域包括：（i）流体弹性（或流入）主导的内壁区域;（ii）流体弹性（或流入）主导的外壁区域;以及（iii）流入/流出核心区域。基于这一观察，一个简单的机制，惯性-弹性湍流TC流已被假定。
Abstract Direct numerical simulation (DNS) of elastically induced turbulent flows has posed great challenges to researchers engaged in developing first-principle models and simulations that can predict faithfully the complex spatio-temporal dynamics of polymeric flows. To this end, DNS of elastically induced turbulent flow states in the Taylor–Couette (TC) flow are reported here with the aim of paving the way for a mechanistic understanding of this new class of flows. Specifically, the DNS not only faithfully reproduce the key feature of elastically induced turbulent flows, namely, substantial excitation of fluid motion at the smallest temporal and spatial scales, but also for the first time demonstrate the existence of three distinct flow regions in the gap for the inertio-elastic turbulence state: (i) a fluid-inertia (or outflow-) dominated inner-wall region; (ii) a fluid-elasticity (or inflow-) dominated outer-wall region; and (iii) an inflow/outflow core region. Based on this observation, a simple mechanism for the inertio-elastic turbulence in the TC flow has been postulated.