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Updated: Jun 23, 2025

Forming, Confining, and Observing Microtubule-Based Active Nematics
Published on: January 13, 2023
Analysis of the number of topological defects in active nematic fluids under applied shear flow
Zhenna Li1, Hao Ye1, Jianzhong Lin2,3
1State Key Laboratory of Fluid Power Transmission and Control, Zhejiang University, Hangzhou, 310027, China.
Abstract:
The number of topological defects in the shear flow of active nematic fluids is numerically investigated in this study. The evolution of the flow state of extensile active nematic fluids is explored by increasing the activity of active nematic fluids. Evidently, medium-activity active nematic fluids exhibit a highly ordered vortex lattice fluid state. However, high-activity active nematic fluids exhibit a meso-scale turbulent flow accompanied by topological defects. The number of topological defects (Ndef) increases with increasing shear Reynolds number (Res). Fluid viscosity strongly influences Ndef, while the influence of fluid density is relatively weak. Ndef decreases with increasing activity length scale (lζ) value. A small Res value strongly influences Ndef, whereas a large lζ value only weakly influences Ndef. As the activity increases, Ndef in contractile active nematic fluids becomes larger than that of extensile active nematic fluids.
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