A numerical investigation of the fluid mechanical sewing machine
A numerical investigation of the fluid mechanical sewing machine
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DOI：
10.1063/1.3703316
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发表时间：
2012-04-01
影响因子：
4.6
通讯作者：
Audoly, B.
中科院分区：
文献类型：
--
作者：
Brun, P. -T.;Ribe, N. M.;Audoly, B.
一条细长的粘性流体落在移动的皮带上，会产生令人惊讶的各种图案，这取决于皮带的速度、下落高度、流速和流体性质。在这里，我们使用离散粘性线方法对该实验进行了数值模拟，该方法可以预测粘性细丝的非定常动力学，捕捉到惯性和拉伸、弯曲和扭曲变形的综合影响。我们的模拟成功地再现了实验室中以前看到的十种不同图案中的九种，并与Morris[Phys]的实验相图非常一致。修订本E 77,066218(2008年)]。基于丝带接触点的纵向和横向运动的傅里叶谱，我们提出了一种新的花纹分类方法。在大多数情况下，这些频率似乎与在零皮带速度极限下获得的稳定卷取的频率欧米茄(C)的简单比率锁定。特别是，有趣的“交替循环”模式是由欧米茄(C)/3的前五个倍数组合而成的。(C)2012年美国物理研究所。[http://dx.doi.org/10.1063/1.3703316]
A thin thread of viscous fluid falling onto a moving belt generates a surprising variety of patterns depending on the belt speed, fall height, flow rate, and fluid properties. Here, we simulate this experiment numerically using the discrete viscous threads method that can predict the non-steady dynamics of thin viscous filaments, capturing the combined effects of inertia and of deformation by stretching, bending, and twisting. Our simulations successfully reproduce nine out of ten different patterns previously seen in the laboratory and agree closely with the experimental phase diagram of Morris [Phys. Rev. E 77, 066218 (2008)]. We propose a new classification of the patterns based on the Fourier spectra of the longitudinal and transverse motion of the point of contact of the thread with the belt. These frequencies appear to be locked in most cases to simple ratios of the frequency Omega(c) of steady coiling obtained in the limit of zero belt speed. In particular, the intriguing "alternating loops" pattern is produced by combining the first five multiples of Omega(c)/3. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3703316]