A 3D isogeometric BE-FE analysis with dynamic remeshing for the simulation of a deformable particle in shear flows

A three-dimensional isogeometric coupled boundary element and finite element approach based on analysis suitable T-splines is developed for the simulation of deformable capsules suspended in shear flows. Boundary element analysis is used to solve the fluid Stokes equation whereas the hydrodynamic membrane load is computed via isogeometric analysis under the assumption that the membrane is a hyper-elastic thin shell with negligible bending resistance. The smoothness of the T-spline basis functions accommodate large deformations of the capsule without the need for additional smoothing techniques, and can be used to accurately compute the membrane load. A balanced distribution of membrane elements can be constructed using an unstructured locally refined mesh. These properties are coupled with an adaptive temporal implicit integration scheme. Several benchmark examples are solved to illustrate the accuracy and potential of the method. The approach is then applied to simulate the dynamics of a capsule in a real geometry of a brain capillary.