Work

Numerical Analysis of Orientational Behavior of Particles Exhibiting Rheotaxis in Unsteady Uniform Flows

Year: 2026

Type: article

Abstract: The flow-induced structure of suspensions of particles exhibiting rheotaxis in a uniform flow was numerically analyzed. A startup flow and a flow with step changes in the flow direction were considered. The particles were self-propelled and rotated in the flow. The computational model for particle rotation includes rotation in the direction opposite to the flow, alignment with the average direction of surrounding particles within an effective region, and random rotation. The effect of the intensity of both rheotaxis and random motion of particles on their orientation in a uniform flow was analyzed. The particles move to orient themselves in the direction opposite to the flow with time, increasing the orientation order of the particle suspension. The orientation order increases as the effect of rheotaxis becomes stronger. Furthermore, it is evident that robustness of the orientational behavior to noise intensifies even for weak rheotaxis. In a flow in which the flow direction changes, the director rotates more slowly for systems exhibiting weaker rheotaxis and the particles rotate in a more synchronized manner when rheotaxis is strong.

Source: Nihon Reoroji Gakkaishi

DOI: 10.1678/rheology.54.1

Author: Takehiro Yamamoto

Institution: Osaka Electro-Communication University

Language: English

Topic: Micro and Nano Robotics

Subfield: Condensed Matter Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: diamond

Funder: Japan Society for the Promotion of Science

Award: Numerical analysis of collective motion and flow-induced structure in dispersion system of biological particles with taxis