非定常高せん断流れ場における変形挙動を再現する赤血球モデルの構築(流体工学,流体機械)

概要

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We developed a computational model that expresses a deformation behavior of a red blood cell (RBC) in a high shear flow. The RBC was modeled as a capsule of spring-networks that has a mechanical nature of lipid bilayer and spectrin. Besides bending and stretching of the membrane, area and volume constraints were imposed in order to assure their incompressibility. Fluid forces exerted by external plasma and internal hemoglobin were estimated based on the momentum conservation and Newton's law of viscosity. Given a flow field, the behavior of RBC was determined toward the minimum energy state. In the Couette flow, the RBC was stretched with a tank-tread rotation of the membrane. A good agreement with experimental data was obtained by using a nonlinear spring for the stretch where a spring constant changes as a function of stretch ratio. In the cyclically reversing unsteady shear flow at a frequency of 1, 2, 3 and 5Hz, the RBC deformed in concert with a change in the flow field. The time lag on the RBC deformation as well as the deformation index well agreed with experimental results both qualitatively and quantitatively. Those results demonstrate capability of the proposed RBC model.
2010-12-25