Simulation of sperm-like microswimmers using finite element method

Document Type : Research Article

Authors

1 Faculty of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran

2 Department of Mechanical and Aerospace Engineering, Monash University, Melbourne, Australia

3 Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran

Abstract

This research investigates the motion of microorganisms in an incompressible Newtonian fluid using the finite element method in 2D and 3D. The undulating motion generated inside a microswimmer's tail creates hydrodynamic forces within the fluid, which its reaction force propels the microswimmer forward. The Navier-Stokes equation is coupled to Newton's law and solved in the computational domain to simulate the microswimmer's motion. In the first part of this study, the effect of geometric parameters (channel width) and wave parameters (wave amplitude and wavelength) on the swimmer's velocity was investigated. The obtained results indicated that the trend of velocity changes in 2D is not predictable, and the channel height affects this relationship significantly. In the second part of this study, the synchronized swimming phenomenon in 2D and 3D was investigated using the developed model. The results showed that the average swimming velocity in 2D side-by-side, 3D side-by-side, and 3D top-bottom configurations increases by 12%, decreases by 10% and increases by 7%, respectively. Finally, by examining the pressure distribution in the computational domain, it can be concluded that the force dipoles created by the microswimmers' undulating tails, and their position, are the reason behind the increase or decrease of the average swimming velocity.

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