A lattice Boltzmann method (LBM) for two-phase fluid flows containing solid bodies with viscoelastic membrane shell is proposed. The method is based on the two-phase LBM, in which one phase is regarded as solid phase. It is assumed that the bodies have viscoelastic membrane shell and that the membrane is composed of identical imaginary particles which are connected with their neighboring particles by spring. Using this method, we first calculate behavior of a solid body under simple shear flows. It is found that the body becomes an oriented and elongated elliptic shape and then the membrane is driven into a motion around the body like a caterpillar, which is generally called tank-tread motion. We next simulate the motion of the body in plane Poiseuille flows. When a flexible circular body with viscoelastic annular membrane flows downstream in the channel, it is deformed into a concave shape on the upstream side and a convex shape on the downstream side. These results indicate the capability of the present LBM to simulate complex behavior of a solid body in fluid flows, such as red blood cell motion in blood flows.
粘弾性皮膜をもつ固体を含む流れの二相系格子ボルツマン法
