Degonville Maximilien, Boedec Gwenn, Leonetti Marc
Aix Marseille Univ, CNRS, Centrale Marseille, IRPHE UMR 7342, 13384, Marseille, France.
Univ. Grenoble Alpes, CNRS, Grenoble INP, LRP, Grenoble, France.
Eur Phys J E Soft Matter. 2019 Sep 5;42(9):116. doi: 10.1140/epje/i2019-11881-0.
Vesicles are micrometric soft particles whose membrane is a two-dimensional incompressible fluid governed by bending resistance leading to a zoology of shapes. The dynamics of deflated vesicles in shear flow with a bottom wall, a first minimal configuration to consider confined vesicles, is investigated using numerical simulations. Coexistence under flow of oblate (metastable) and prolate (stable) shapes is studied in details. In particular, we discuss the boundaries of the region of coexistence in the (v, Ca -plane where v is the reduced volume of the vesicle and Ca the Capillary number. We characterize the transition from oblate to prolate and analyse the divergence of the transition time near the critical capillary number. We then analyse the lift dynamics of an oblate vesicle in the weak flow regime.
囊泡是微米级的软颗粒，其膜是一种二维不可压缩流体，由弯曲阻力控制，从而产生各种形状。使用数值模拟研究了在具有底壁的剪切流中瘪囊泡的动力学，这是考虑受限囊泡的第一种最小构型。详细研究了扁球形（亚稳）和长球形（稳定）形状在流动下的共存情况。特别是，我们讨论了共存区域在（v，Ca）平面中的边界，其中v是囊泡的折合体积，Ca是毛细管数。我们表征了从扁球形到长球形的转变，并分析了临界毛细管数附近转变时间的发散情况。然后，我们分析了弱流 regime 中扁囊泡的升力动力学。
