Segregation of charged bidispersed particles and generation of intermittent electric fields in turbulence

From striking lightning in the electrified clouds to tribocharged dust particles in the sandstorm, turbulent flows laden with charged particles are prevalent in a wide range of natural phenomena and industrial applications. However, the effects of electrostatic interaction on charged particle behavior in turbulence remains less understood, and the connection between the resulting electric fields and the turbulent structures is also unclear. To address this issue, we conduct experimental investigations in homogeneous isotropic turbulence seeded with bidispersed particles carrying opposite charges. Instantaneous particle locations are accurately captured using Lagrangian particle tracking (LPT) allowing us to directly measure turbulence-driven segregation of bidispersed particles with and without electric charges. Based on the datasets, the dependence of size segregation on the competition between the electrostatic forces and the particle-turbulence interactions is further characterized. Finally, by assigning a known charge to each particle, the three-dimensional electric fields are reconstructed, and their statistics are discussed providing insights into the intrinsic relationship between intermittent electric field and turbulent coherent structures.