Numerical Investigation of Electrostatic Effect on Particle Dispersion in Turbulent Pipe Flows

Yanlin Zhao, Jinzhui Li, Jun Yao

Beijing Key Laboratory of Process Fluid Filtration and Separation, College of Mechanical and Transportation Engineering, China University of Petroleum-Beijing, 18 Fuxue Road, Changping, Beijing, 102249, People’s Republic of China

* Corresponding author, Email address: yaojun@cup.edu.cn (J.Yao)

Keywords: Electrostatics, Numerical simulation, Particle dispersion, Turbulence

Abstract

The electrostatic effect on particle dispersion in turbulent pipe flows with an additional electrostatic field generated by particle-particle and particle-wall collisions is investigated by RANS approach, combined with a Lagrangian tracking technique of one-way coupling. Particle motion equation is governed by drag force, gravity, lift force and electrostatic force. A wide range of particle size (50~ 2800μm) at three high Reynolds number cases (Re=31k, 39k, 58k) are considered. Results obtained for the single-phase flow show good agreement with the available experimental and numerical data. Three particle-laden flow patterns can be found within the Reynolds number range studied, which agrees well with previous experimental observation. It is found that particles tend to move toward the pipe walls under the effect of electrostatic force and some of them stick to the wall in the end. In addition, the electrostatic force is observed to promote particle dispersion first and then inhibit it independent of Reynolds number and particle size. A dynamic analysis demonstrates that particle dispersion in near-wall regions is dominated by the electrostatic force rather than other forces because its magnitude is at least two orders larger than others.