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Microswimmer locomotion and hydrodynamics in Brinkman flows
Francisca Guzmán-Lastra1, Enkeleida Lushi2
1Universidad de Chile, Departamento de Física, Facultad de Ciencias, Santiago, Chile.
Physical Review. E
|December 23, 2025
Summary
Microswimmers slow down in complex fluids due to medium resistance. Analytical models reveal how porous media affect locomotion and flow fields, aiding future studies.
Area of Science:
- * Biological Physics
- * Fluid Dynamics
- * Microorganism Locomotion
Background:
- * Microorganism movement in complex environments is crucial in biological physics.
- * Brinkman fluid models porous media with stationary obstacles using a linear resistance term.
- * Understanding microswimmer behavior in such media requires robust theoretical frameworks.
Purpose of the Study:
- * To investigate microswimmer locomotion and flow fields in Brinkman fluid.
- * To analyze a dumbbell swimmer model and derive its velocity dependence on medium resistance.
- * To develop analytical expressions for flow fields generated by force dipoles in Brinkman media.
Main Methods:
- * Modeling a dumbbell swimmer with spring-connected spheres and flagellar force.
- * Deriving swimming velocity as a function of Brinkman medium resistance.
- * Calculating the far-field flow generated by a Brinkmanlet force dipole.
Main Results:
- * Microswimmer velocity decreases monotonically with increasing Brinkman medium resistance.
- * Hydrodynamic interactions are screened in finite resistance media, attenuating long-range effects.
- * An analytical expression for the Brinkmanlet force dipole flow field accurately approximates the dumbbell swimmer's far-field flow.
Conclusions:
- * The study provides analytical tools for understanding microswimmer locomotion in complex fluids.
- * Findings offer foundational insights into collective behavior in active and passive suspensions.
- * The Brinkman fluid model effectively captures the impact of porous media on microswimmer dynamics.
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