Electronic Thesis and Dissertation Repository

Degree

Doctor of Philosophy

Program

Electrical and Computer Engineering

Supervisor(s)

Dr. Kazimierz Adamiak

Abstract

One of the main goals of applied electrostatics engineering is to discover new perspectives in a wide range of research areas. Controlling the fluid media through electrostatic forces has brought new important scientific and industrial applications. Electric field induced flows, or electrohydrodynamics (EHD), have shown promise in the field of fluid dynamics. Although numerous EHD applications have been explored and extensively studied so far, most of the works are either experimental studies, which are not capable to explain the in depth physics of the phenomena, or detailed analytical studies, which are not time effective. The focus of this study is to provide the model that in a reasonable computational time is able to give us accurate results in different electric-fluid interactions. So, the main goals of this study is to provide a model to simulate all essential physical phenomena, applicable in different EHD systems.

So, in this thesis, first, a two-dimensional numerical solver is presented for the dynamic simulation of the Dielectric Barrier Discharge (DBD) and the Corona Discharge (CD) in point to plane configuration. The simulations start with the single-species model and the different steps of the numerical technique are tested for this simplified model. The ability of the technique to model the expected physical behavior of ions and electric field is investigated. The studied physics were implemented in different geometry configurations such as wire to plane, wire to wire, and plane to plane geometries. The electrostatic field and ionic space charge density due to corona discharge were computed by numerically solving Poisson and current continuity equations, using a Finite Element method (FEM). The detailed numerical approach and simulation procedure is discussed and applied throughout the thesis. Then, the technique is applied to a more complicated model in order to address several existing EHD applications. The complicated mutual interaction between the three coexisting phenomena of electrostatic field, the charge transport, and fluid dynamics, which affect the EHD process, were taken into account in all the simulations. Calculations of the gas flow were carried out by solving the Reynolds-averaged Navier-Stokes (RANS) equations using FEM. The turbulence effect was included by using the k-ε model included in commercial COMSOL software. An additional source term was added to the gas flow equation to include the effect of the electrostatic body force. In all the simulations, the effects of different parameters on the overall performance of the system and its characteristics are investigated. In some cases, the simulation results were compared with the existing experimental data published in literature.