Applied Electrostatics & Electromagnetics
The Applied Electrostatics and Electromagnetics Research Group is the oldest one in the Department of Electrical and Computer Engineering, the University of Western Ontario (UWO). It involves two areas: applied electrostatics and electromagnetics, and in both areas this research group is internationally acclaimed. The record of achievements includes a large number of publications, many patents, three IEEE fellowships, two honorary doctorates, merit awards, a high level of research grants and numerous industrial contracts.
One part of this research group is organized in the Applied Electrostatics Research Centre (AERC), which is one of the few in the world specializing in the application of electrostatics to interdisciplinary problems. The members of the Centre cover all the engineering disciplines. The majority of the research activities undertaken have been primarily motivated by an interest in applying electric force phenomena to industrial and societal problems. Recent analytical and experimental studies focus on electrical charging of particles, modeling of electrostatic and electromagnetic fields, and solutions for problems ranging from agricultural spraying, to air pollution control with electrostatic precipitators, chemistry of electro ozonation, strengthening of clay foundations by dielectrophoretic extraction of water, through to methods for controlling electrostatic discharges. The other part of the group is interested in the general area of electromagnetics: this includes radio-wave propagation, radars and stochastic electromagnetics. Much of this work is also interdisciplinary and involves collaborative work with researchers in the Department of Physics.
AREAS OF STRENGTH
Electrostatic processes commonly occur in many industrial applications; often they can significantly improve the process quality. The group activity involves fundamental studies, practical developments and consulting services for the industrial partners. The AERC specializes also in the detection and prevention of electrostatic hazards. Different charging techniques have been investigated for small solid particles, liquid droplets and larger objects. These have included studies involving tribocharging, induction, conduction and corona charging. The charged objects can be then manipulated using the electric forces. The research concentrates on topics such as electrostatic painting and coating, plastic separation, electromechanics of particles, air cleaning, mineral separation, electrophotography and gas discharges. The electric fields can also affect the process of droplet formation and distribution, such as in the case of agricultural spraying, or initiate some chemical reactions, for example in generating ozone for water purification or treatment of flue gases.
A significant research effort has been connected with tropospheric microwave propagation and the angle-of-arrival of the several components in a multipath environment. Intimately connected with this was the development and deployment of a sophisticated vertical interferometer system. This has application in communications and in low-angle radar work. Recently, undesired effects of electromagnetic radiation have become an important issue in design of medical and communication equipment. Due to complexity and uncertainty in configuration of such equipment the deterministic approach is being supplanted by stochastic description and evaluation. The research group focuses on the evaluation of impact of EM radiation on complex systems and design of electromagnetic reverberation chambers.
Electrostatic discharge is a major reliability concern in electronic devices and systems. The complexity of research required in the field continues to evolve as the feature sizes of integrated circuits are reduced and clock frequencies of digital systems increase. Research includes fundamental studies, development of protection methodologies, discharge physics and electromagnetic interference. Recently, the study of micro gap discharge phenomena has become important with application in high-density magnetoresistive recording heads and micro-electromechanical systems.
Gas Discharges and Electrohydrodynamics
Different numerical algorithms have been applied to simulate the corona discharge in different configurations: wire-plate electrostatic precipitator, AC charger for small particles, triode system, point-plane and others. More recently, the research concentrates on including phenomena occurring in the ionization layer, more complicated geometries of the discharge electrodes and including multi-species charge transport. Moving ions, produced by the corona discharge, induce the gas motion, which can affect other processes: particle motion, dust deposition and heat exchange. The numerical modeling of this phenomenon includes not only the electric field, but also the fluid dynamics equations and a numerical algorithm has been already created for the gaseous media. The EHD flow in fluids generates a two-way coupling between the electric field and fluid flow. This requires much more complicated computational modeling than has been traditionally used.
Currently, the Group facilities are fully equipped with the necessary instrumentation and equipment for carrying out projects related to the industrial generation, application and control of electric forces. In addition, the Group has full access to facilities in other UWO Departments and Centres.
All members of the Group have NSERC individual discovery grants. Several members have been successful in other grant applications, including the NSERC strategic and NATO collaborative research grants.
COLLABORATIONS AND INDUSTRY LINKS
The group research has resulted in precise methods for controlling the movements of particulates such as aerosols, ink toners, water droplets and other fine materials, by applying electrical charges to the particulates. Recent industrial and government clients include INCO, Ontario Hydro, Blue Circle Industries (U.K.), Potash Corporation of Saskatchewan, I.B.M., Nordson Corporation (U.S.A.), Toyota Motor Manufacturing (Canada), Ciba-Geigy (Switzerland), B.C. Hydro, Atochem (France), Biotech, St. Gobain Abrasives, GM Research, the Ontario Ministry of the Environment and the Federal Department of Supply and Services for Energy, Mines and Resources Canada and Agriculture Canada, Dupont, Kirby. Listed below are some examples of topics of projects that have been carried out:
- Electrostatic precipitation
- Plastic separation
- Air filtration
- Electrostatic separation
- Electrostatic painting and coating
- Electrostatic hazards
- Electrostatic agricultural spraying
- Measurement techniques (resistivity measurements of fly ash, SO2 monitoring using electronegativity, dust concentration and space charge density, bipolar charge measurement in powders)
Applied Electrostatics is truly interdisciplinary group; in addition to five core members from the Department of Electrical and Computer Engineering (I.I. Inculet, G.S.P. Castle, W.D. Greason, Z. Kucerovsky and K. Adamiak), many other faculty members from the Departments Chemical and Biochemical (M. A. Bergougnou and C. Briens), and Mechanical and Materials Engineering (J.D. Brown and M. Floryan), as well as from the Department of Mechanical Engineering in the University of Waterloo (B. Weckman), also participate in the Centre research projects.
The research work on the gas discharges and electrohydrodynamics is carried out in collaboration with the Institute of Fluid Flow Machinery of the Polish Academy of Science in Gdansk, Poland, Laboratoire d'Electrostatique et de Materiaux Dielectriques, CNRS in Grenoble, France and the Institute of High Temperatures, the Russian Academy of Science in Moscow, Russia. Especially the research contacts with the French group are of high value as it is generally considered as the world leader on gas discharges and dielectrics.
The meteor modelling work is done in collaboration with the National Aeronautics and Space Administration (NASA) in Huntsville, Alabama and, quite recently, with the Communications Research Centre in Ottawa; both of these activities involve Dr. J. Jones in the Department of Physics, U.W.O.