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Updated: May 10, 2026
09:24
A Rapidly Incremented Tethered-Swimming Maximal Protocol for Cardiorespiratory Assessment of Swimmers
Published on: January 28, 2020
Active temperature and velocity correlations produced by a swimmer suspension
1Departamento de Física, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Casilla 487-3, Santiago, Chile.
Summary
Microswimmers create fluid agitation, characterized by active temperature and velocity correlations. These properties depend on the dipole-dipole correlation function and system size, with distinct behaviors in 2D and 3D.
Area of Science:
- Soft Matter Physics
- Fluid Dynamics
- Statistical Mechanics
Background:
- Microswimmers generate fluid motion, particularly in low Reynolds number regimes.
- Understanding fluid agitation is crucial for applications involving active matter.
Purpose of the Study:
- To investigate fluid agitation caused by microswimmers at low Reynolds numbers.
- To characterize agitation using active temperature and velocity correlations.
- To analyze the dependence of these properties on microswimmer distribution and system size.
Main Methods:
- Modeling microswimmers as equal-strength force dipoles.
- Analyzing homogeneous and isotropic microswimmer distributions.
- Utilizing a medium-range order model with a single correlation length.
- Calculating active temperature and spatial velocity correlations.
Main Results:
- Active temperature and velocity correlations depend on the dipole-dipole correlation function.
- Active temperature scales with system size L as L^(4-d) at large correlation lengths.
- In 3D, velocity correlations decay as 1/r, with negative transverse correlations at large separations.
Conclusions:
- A quantitative model for microswimmer-induced fluid agitation is established.
- System size and correlation length significantly influence active temperature and velocity correlations.
- Emergent phenomena like negative transverse correlations are observed in 3D systems.
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