School of Physics, Trinity College Dublin, Dublin 2, Republic of Ireland.
J Phys Condens Matter. 2010 May 19;22(19):193101. doi: 10.1088/0953-8984/22/19/193101. Epub 2010 Apr 23.
We review some recent advances in the rheology of two-dimensional liquid foams, which should have implications for three-dimensional foams, as well as other mechanical systems that have a yield stress. We focus primarily on shear localization under steady shear, an effect first highlighted in an experiment by Debrégeas et al. A continuum theory which incorporates wall drag has reproduced the effect. Its further refinements are successful in matching results of more extensive observations and making interesting predictions regarding experiments for low strain rates and non-steady shear. Despite these successes, puzzles remain, particularly in relation to quasistatic simulations. The continuum model is semi-empirical: the meaning of its parameters may be sought in comparison with more detailed simulations and other experiments. The question of the origin of the Herschel-Bulkley relation is particularly interesting.
我们回顾了二维液体泡沫流变学的一些最新进展，这些进展应该对三维泡沫以及其他具有屈服应力的机械系统有影响。我们主要关注稳态剪切下的剪切局部化，这一效应最初是由 Debrégeas 等人的实验中提出的。一个包含壁面阻力的连续体理论重现了这一效应。进一步的改进成功地匹配了更广泛观察结果，并对低应变速率和非稳态剪切实验做出了有趣的预测。尽管取得了这些成功，但仍存在一些难题，特别是在准静态模拟方面。连续体模型是半经验性的：其参数的意义可以通过与更详细的模拟和其他实验进行比较来寻求。Herschel-Bulkley 关系的起源问题尤其有趣。
