A necklace model for vesicles simulations in 2D

The aim of this paper is to propose a new numerical model to simulate 2D vesicles interacting with a Newtonian fluid. The inextensible membrane is modeled by a chain of circular rigid particles, which are maintained in cohesion by using two different types of forces. First, a spring force is imposed between neighboring particles in the chain. Second, in order to model the bending of the membrane, each triplet of successive particles is submitted to an angular force. Numerical simulations of vesicles in shear flow have been run using FEM and the FreeFem++ software. Exploring different ratios of inner and outer viscosities, we recover the well‐known ‘tank‐treading’ and ‘tumbling’ motions predicted by a theory and experiments. Moreover, for the first time, 2D simulations of the ‘vacillating‐breathing’ regime without special ingredient such as thermal fluctuations are recovered. Copyright © 2014 John Wiley & Sons, Ltd.