Mathematical modelling of glob-driven tear film breakup.
Mathematical modelling of glob-driven tear film breakup.
复制标题
球驱动泪膜破裂的数学模型。
DOI：
10.1093/imammb/dqx021
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
King-Smith,PE
中科院分区：
文献类型：
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作者：
Zhong,L;Ketelaar,CF;Braun,RJ;Begley,CG;King-Smith,PE
蒸发是公认的泪膜变薄和泪水破裂(TBU)的因素。最近，观察到了一种不同类型的TBU，在眨眼后一秒钟内，TBU发生在厚厚的脂质区域下面或周围。厚厚的脂类与球状结构相对应。单靠蒸发速度太慢，不能完全解释这种分裂。有人认为，泪膜迅速变薄的主要原因是由较低的球体表面张力(通过Marangoni效应)驱动的发散流。我们在一维条纹模型和轴对称光斑模型中检验了球体驱动的TBU假说。在该模型中，条纹或斑点球体具有局部较高的表面活性剂浓度，这被认为可以降低泪水/空气的表面张力，并且具有固定的尺寸。条纹和斑点模型都表明，Marangoni效应可以导致强烈的切向流离开球体，并可能导致TBU。模型预测，较小的球体或较薄的薄膜将减少TBU时间(T BUT)。TBU位于小球体之下，但可能出现在大球体之外。除了切向流外，蒸发也会对总蒸发量产生影响。这项研究提供了关于快速变薄的机制和眨眼后非常迅速发生的TBU的见解，以及球体的性质如何影响tBUT。
Evaporation is a recognized contributor to tear film thinning and tear breakup (TBU). Recently, a different type of TBU is observed, where TBU happens under or around a thick area of lipid within a second after a blink. The thick lipid corresponds to a glob. Evaporation alone is too slow to offer a complete explanation of this breakup. It has been argued that the major reason of this rapid tear film thinning is divergent flow driven by a lower surface tension of the glob (via the Marangoni effect). We examine the glob-driven TBU hypothesis in a 1D streak model and axisymmetric spot model. In the model, the streak or spot glob has a localized high surfactant concentration, which is assumed to lower the tear/air surface tension and also to have a fixed size. Both streak and spot models show that the Marangoni effect can lead to strong tangential flow away from the glob and may cause TBU. The models predict that smaller globs or thinner films will decrease TBU time (TBUT). TBU is located underneath small globs, but may occur outside larger globs. In addition to tangential flow, evaporation can also contribute to TBU. This study provides insights about mechanism of rapid thinning and TBU which occurs very rapidly after a blink and how the properties of the globs affect the TBUT.