Flow-Induced Deformation of 3D Elastic Capsules

We present an improved penalty immersed boundary (pIB) method for simulation of flow-induced deformation of 3D elastic capsules. The membrane deformation takes full account of the bending and twisting effects as well as the stretching and shearing effects. Hence, the method of subdivision surfaces is adopted to generate the mesh of membrane and the corresponding shape functions, which are required to be C-1 continuous. Using the proposed pIB method, the deformation of 3D elastic capsules in simple shear flow is studied in detail. For an initially spherical capsule the steady tank-treading motion is formed, in which the capsule maintains constant shape and orientation but rotates around the interior fluid. Time histories of the deformation parameter at various dimentionless shear rates and reduced bending moduli are presented and compared with data from previous studies.