论文标题
在振荡剪切流下红细胞悬浮液的粘弹性
Viscoelasticity of suspension of red blood cells under oscillatory shear flow
论文作者
论文摘要
我们介绍了红细胞悬浮液（RBC）的流变学分析的数值分析，用于在壁构造的，有效惯性的，小振幅振动剪切（SAOS）流动中，用于广泛的施加频率。 RBC被建模为Biconcave胶囊，其膜是遵循Skalak构成定律的各向同性和超弹性材料。大容量悬浮液中频率依赖性的粘弹性通过复杂的粘度来量化，该复杂粘度由粒子剪切应力的幅度以及应力和剪切之间的相位差定义。 SAOS流基本上会阻碍单个RBC的变形以及流体 - 膜相互作用的大小，从而导致比稳定的剪切流动较低的特异性粘度和第一和第二正常应力差异。尽管众所周知，仅RBC变形足以产生剪切幅度，但我们的结果表明，复杂的粘度弱取决于频率调制的单个RBC的变形或方向，而取决于频率依赖性振幅和相位差的组合。还评估了细胞质和血浆与毛细血管数之间的粘度比的影响。
We present a numerical analysis of the rheology of a suspension of red blood cells (RBCs) for different volume fractions in a wall-bounded, effectively inertialess, small amplitude oscillatory shear (SAOS) flow for a wide range of applied frequencies. The RBCs are modeled as biconcave capsules, whose membrane is an isotropic and hyperelastic material following the Skalak constitutive law. The frequency-dependent viscoelasticity in the bulk suspension is quantified by the complex viscosity, defined by the amplitude of the particle shear stress and the phase difference between the stress and shear. SAOS flow basically impedes the deformation of individual RBCs as well as the magnitude of fluid-membrane interactions, resulting in a lower specific viscosity and first and second normal stress differences than in steady shear flow. Although it is known that the RBC deformation alone is sufficient to give rise to shear-thinning, our results show that the complex viscosity weakly depends on the frequency-modulated deformations or orientations of individual RBCs, but rather depends on combinations of the frequency-dependent amplitude and phase difference. The effect of the viscosity ratio between the cytoplasm and plasma and of the capillary number are also assessed.
