Modeling the Rheological Properties of a Red Cell Suspension in a Simple Shear Flow
Chih-Tang Liao1*, Yeng-Long Chen2
1Engineering and System Science, National Tsing Hua University, Hsinchu, Taiwan
2Institute of Physics, Academia Sinica, Taipei, Taiwan
* presenting author:Chih-Tang Liao,
We apply the lattice Boltzmann method coupled with a coarse-grained membrane model to conduct numerical experiments on the rheology of a suspension of aggregation-free red blood cells (RBCs) in a simple shear flow. We attempt to capture experimentally observed suspension viscosity dependence on the shear rate and particle volume fraction. On the basis of this model, adhesive force among RBCs will be taken into account to study consequences of RBC aggregation (also called rouleaux) in our follow-up work. We find that the suspension viscosity increases nonlinearly with the particle volume fraction. Our model also successfully captures the shear-thinning behavior of the suspension as the shear rate increases, in qualitative agreement with experimental observations. The normal components of particle stress increases and the particle pressure decreases as the shear rate increases. These are attributed to flow-induced RBC alignment and weaker inter-particle interaction at larger shear rates.

Keywords: Suspension, Rheology, Red blood cell