Rahmani Yasser, Habibi Mehdi, Javadi Arman, Bonn Daniel
Department of Physics, Institute for Advanced Studies in Basic Sciences, Zanjan 45137-66731, Iran.
Phys Rev E Stat Nonlin Soft Matter Phys. 2011 May;83(5 Pt 2):056327. doi: 10.1103/PhysRevE.83.056327. Epub 2011 May 31.
We present an experimental investigation of the coiling of a filament of a yield stress fluid falling on a solid surface. We use two kinds of yield stress fluids, shaving foam and hair gel, and show that the coiling of the foam is similar to the coiling of an elastic rope. Two regimes of coiling (elastic and gravitational) are observed for the foam. Hair gel coiling, on the other hand, is more like the coiling of a liquid system; here we observe viscous and gravitational regimes. No inertial regime is observed for either system because of instabilities occurring at high flow rates or the breakup of the filament from large heights.
我们展示了对屈服应力流体细丝落在固体表面上时的卷曲现象进行的实验研究。我们使用了两种屈服应力流体，剃须泡沫和发胶，并表明泡沫的卷曲类似于弹性绳索的卷曲。对于泡沫，观察到两种卷曲状态（弹性和重力）。另一方面，发胶的卷曲更类似于液体系统的卷曲；在这里我们观察到粘性和重力状态。由于在高流速下出现不稳定性或细丝从较大高度断裂，两个系统均未观察到惯性状态。
