Three-dimensional Lattice Boltzmann Simulation of Two-phase Flow Containing a Deformable Body with a Viscoelastic Membrane
The lattice Boltzmann method (LBM) with an elastic model is applied to the
simulation of two-phase flows containing a deformable body with a viscoelastic membrane.
The numerical method is based on the LBM for incompressible two-phase fluid
flows with the same density. The body has an internal fluid covered by a viscoelastic
membrane of a finite thickness. An elastic model is introduced to the LBM in order
to determine the elastic forces acting on the viscoelastic membrane of the body. In the
present method, we take account of changes in surface area of the membrane and in
total volume of the body as well as shear deformation of the membrane. By using this
method, we calculate two problems, the behavior of an initially spherical body under
shear flow and the motion of a body with initially spherical or biconcave discoidal
shape in square pipe flow. Calculated deformations of the body (the Taylor shape parameter)
for various shear rates are in good agreement with other numerical results.
Moreover, tank-treading motion, which is a characteristic motion of viscoelastic bodies
in shear flows, is simulated by the present method.
