Scholarlink

<p>Turbulence in active fluids is a rapidly developing area in active-matter research. Yet the mechanisms and universal statistics of turbulence in a binary mixture of counter-rotating spinners remain unclear. We uncover activity-driven crossover from phase separation to a turbulent state in a two-dimensional system of counter-rotating spinners. This state exhibits spatiotemporal chaos with fluctuating vortex doublets that form, decay, and reappear. We study the statistical properties of this turbulence, using the active-rotor Cahn-Hilliard-Navier-Stokes model, and show that, as the activity increases, the vorticity <i>ω</i>&#xa0;∝&#xa0;<i>ϕ</i>, the scalar field that distinguishes regions with clockwise- and counter-clockwise rotation. Using direct numerical simulations, we characterize the power-law forms of fluid-energy spectra and show they are significantly different from those in fluid and bacterial turbulence. In addition to presenting evidence for small-scale intermittency in active-rotor turbulence, we characterize flow-topology statistics and contrast it with that in 2D fluid turbulence. Subsequently, we propose experimental tests for our predictions, and suggest biological implications of active-rotor turbulence.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Emergent turbulence and coarsening arrest in active-spinner fluids

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2025年11月29日

查看全文
  • Biswajit Maji,
  • Nadia Bihari Padhan,
  • Rahul Pandit

摘要

Turbulence in active fluids is a rapidly developing area in active-matter research. Yet the mechanisms and universal statistics of turbulence in a binary mixture of counter-rotating spinners remain unclear. We uncover activity-driven crossover from phase separation to a turbulent state in a two-dimensional system of counter-rotating spinners. This state exhibits spatiotemporal chaos with fluctuating vortex doublets that form, decay, and reappear. We study the statistical properties of this turbulence, using the active-rotor Cahn-Hilliard-Navier-Stokes model, and show that, as the activity increases, the vorticity ω ∝ ϕ, the scalar field that distinguishes regions with clockwise- and counter-clockwise rotation. Using direct numerical simulations, we characterize the power-law forms of fluid-energy spectra and show they are significantly different from those in fluid and bacterial turbulence. In addition to presenting evidence for small-scale intermittency in active-rotor turbulence, we characterize flow-topology statistics and contrast it with that in 2D fluid turbulence. Subsequently, we propose experimental tests for our predictions, and suggest biological implications of active-rotor turbulence.