The cross-stream inertial migration of neutrally buoyant particles in a power law fluid in a pressure-driven flow between two parallel walls is studied using three-dimensional numerical simulations. The particles are modeled as rigid and compliant spherical shells filled with a Newtonian fluid. Our simulations show that the particles in the flow equilibrate at stable off-center positions that depend on the particle size and fluid power exponent. In a shear thickening fluid, the equilibrium position is insensitive to the particle size. In a shear thinning fluid, an additional unstable off-center equilibrium position emerges for smaller particles, which leads to the accumulation of such particles at the channel centerline. We find that these equilibrium positions are insensitive to the magnitude of the channel Reynolds number and particle elasticity. The results of our study have applications to sorting, focusing, and separation of synthetic particles and biological cells.

中文翻译：

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幂律流体通道流中球形粒子的惯性迁移

使用三维数值模拟研究了两个平行壁之间的压力驱动流中的幂律流体中中性浮力粒子的横流惯性迁移。粒子被建模为充满牛顿流体的刚性且柔顺的球壳。我们的模拟表明，流动中的粒子在稳定的偏心位置平衡，这取决于粒子大小和流体动力指数。在剪切增稠流体中，平衡位置对粒度不敏感。在剪切稀化流体中，对于较小的颗粒，会出现额外的不稳定偏心平衡位置，这会导致此类颗粒在通道中心线处积聚。我们发现这些平衡位置对通道雷诺数和粒子弹性的大小不敏感。