Mixing and transport by ciliary carpets: a numerical study

Abstract

We use a 3D computational model to study the fluid transport and mixing due to the beating of an infinite array of cilia. In accord with recent experiments, we observe two distinct regions: a fluid transport region above the cilia and a fluid mixing region below the cilia tip. The metachronal wave due to phase differences between neighboring cilia is known to enhance the fluid transport above the ciliary tip. In this work, we show that the metachronal wave also enhances the mixing rates in the sub-ciliary region, often simultaneously with the flow rate enhancement. Our results suggest that this simultaneous enhancement in transport and mixing is due to an enhancement in shear flow. As the flow above the cilia increases, shear rate in the fluid increases and such shear enhances stretching, which is an essential ingredient for mixing. Estimates of the mixing time scale indicate that, compared to diffusion, the mixing due to the cilia beat may be significant and sometimes dominates chemical diffusion.

submitted to Journal of Fluid Mechanics

References in corpus (7)

• Finding the ciliary beating pattern with optimal efficiency
• Fluid transport at low Reynolds number with magnetically actuated artificial cilia
• Efficiency optimization and symmetry-breaking in a model of ciliary locomotion
• Kinematics of the most efficient cilium
• Optimal feeding is optimal swimming for all Péclet numbers
• Microfluidic propulsion by the metachronal beating of magnetic artificial cilia: a numerical analysis
• Moving walls accelerate mixing

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