| 研究実績の概要 |
Lateral migration is the movement of a deformable particle perpendicular to the direction of a surrounding fluid flow. In cases when the effect of inertia can be neglected, such as in the microcirculation, only the presence of a wall or shear gradient results in the lateral migration of deformable particles such as cells. For example, in blood flow, red blood cells are observed to migrate away from the blood vessel wall, leading to the formation of a cell-free layer near the wall. On the other hand, the migration of white blood cells and platelets to the vessel wall is essential for bodily functions such as immune functions and coagulation to occur properly. The aim of this research is to clarify the effect of lateral migration with a capsule model for blood cells using a bottom-up approach. In the past year, the following has been accomplished :
Analysis of effect of flow curvature
The lateral migration of capsules in an unbounded Poiseuille flow was compared to that of capsules in a Poiseuille flow placed near a wall. It was shown that, for capsules in an unbounded Poiseuille flow, the lift velocity of the capsule is proportional to a parameter expressing the curvature of the external flow field. Then, comparing the lift velocity of the capsule in an unbounded Poiseuille flow to that of a capsule in a near-wall Poiseuille flow, we derived a relation that expresses the contribution of the flow curvature to the lift velocity of a capsule in a near-wall Poiseuille flow. This relation can be used to determine whether the effect of the flow curvature or presence of a nearby wall can be neglected.
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