Collective Flows Drive Cavitation in Spinner Monolayers

Abstract

Hydrodynamic interactions can give rise to a collective motion of rotating particles. This, in turn, can lead to coherent fluid flows. Using large scale hydrodynamic simulations, we study the coupling between these two in spinner monolayers at weakly inertial regime. We observe an instability, where the initially uniform particle layer separates into particle void and particle rich areas. The particle void region corresponds to a fluid vortex, and it is driven by a surrounding spinner edge current. We show that the instability originates from a hydrodynamic lift force between the particle and fluid flows. The cavitation can be tuned by the strength of the collective flows. It is suppressed when the spinners are confined by a no-slip surface, and multiple cavity and oscillating cavity states are observed when the particle concentration is reduced.

References in corpus (24)

• Collective motion
• Numerical Simulations of Particulate Suspensions via a Discretized Boltzmann Equation Part I. Theoretical Foundation
• Numerical Simulations of Particulate Suspensions via a Discretized Boltzmann Equation Part II. Numerical Results
• Emergence of macroscopic directed motion in populations of motile colloids
• Non-reciprocal phase transitions
• Bacterial hydrodynamics
• Phase behaviour of active Brownian particles: The role of dimensionality
• Dancing Volvox: Hydrodynamic Bound States of Swimming Algae
• Unstable fronts and stable "critters" formed by microrollers
• Motility-Induced Microphase and Macrophase Separation in a Two-Dimensional Active Brownian Particle System
• Collective dynamics in a binary mixture of hydrodynamically coupled micro-rotors
• Flow-induced phase separation of active particles is controlled by boundary conditions
• Self-Organized Critical Coexistence Phase in Repulsive Active Particles
• Purely hydrodynamic ordering of rotating disks at a finite Reynolds number
• Cooperative Self-Propulsion of Active and Passive Rotors
• Leveraging Collective Effects in Externally Driven Colloidal Suspensions: Experiments and Simulations
• Submersed Micropatterned Structures Control Active Nematic Flow, Topology and Concentration
• Fast crystallization of rotating membrane proteins
• Nutrient transport driven by microbial active carpets
• Hyperuniformity and phase enrichment in vortex and rotor assemblies
• Hydrodynamic assembly of active colloids: chiral spinners and dynamic crystals
• Elasticity Induced Force Reversal Between Active Spinning Particles in Dense Passive Media
• Trade-offs in phenotypic noise synchronize emergent topology to actively enhance transport in microbial environments
• Inertial clustering and emergent phase separation of spherical spinners

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