NUMERICAL SIMULATIONS AND ANALYSES OF ELECTROHYDRODYNAMIC FLOWS IN COMPLEX GEOMETRIES

Abstract

Electrohydrodynamics (EHD) deals with the fluid motion induced by an electric field. This thesis aims to study the nonlinear behaviors and linear dynamics of EHD flows in various configurations using direct numerical simulation (DNS) and linear stability analysis.

This thesis first studies the local stability analysis of electro–thermo–hydrodynamic flows between two parallel plates considering a cross-flow, using modal and non-modal tools. Additionally, the two-dimensional EHD flows in the blade-plate configuration are investigated. Through DNS, Moffatt-like eddies are discovered and studied. In addition, global stability analyses are performed to investigate its linear dynamics. Finally, the DNS and global stability analysis of two-dimensional wire-plate EHD flows are presented. Both conduction and injection mechanisms for charge generation are considered in the model. According to the intensity of the cross-flow, the study is categorized into three cases: EHD flows without a cross-flow, with a weak cross-flow, and with a strong cross-flow.