2020/12/26 by Zhengyang Liu, Liu, Zhengyang, Wei Zeng +5 · 2 citations
Engineering · Physics and Astronomy · #FOS: Physical sciences #Fluid Dynamics (physics.flu-dyn) #Micro and Nano Robotics #Microfluidic and Bio-sensing Technologies #Particle Dynamics in Fluid Flows #Soft Condensed Matter (cond-mat.soft)
paper · pdf · doi:10.48550/arxiv.2012.13680
openalex publication_date 2020/12/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We experimentally study density fluctuations and energy spectra of bulk E. coli suspensions of different concentrations. Our results verify the predicted scaling law of giant number fluctuations in three-dimensional (3D) wet active fluids. We find that such a scaling behavior persists at small scales even in low concentration suspensions well below the transition concentration to active turbulence. Our experiments also support the prediction on the energy spectra of dilute pusher swimmers and illustrate the spectral properties of the active turbulence of dense bacterial suspensions in the bulk limit. By comparing density fluctuations and kinetic energy in active turbulence, we identified a universal density-independent and scale-invariant correlation between the two quantities across a wide range of length scales.