Corona, Dielectric Barrier and Sliding Discharges in the Flow Control and Environmental Protection: From Fundamental Studies to Optimization of Practical Devices

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Many processes in industry, medicine and environmental protection involve electrical discharges in gases. The most important devices for our society are probably electrostatic precipitators, which remove dust particles generated in many industrial processes so we may breathe cleaner air. Many toxic substances can also be decomposed using this process. All this is possible, because gas discharges produce free ions and active chemical species. The dust particles can be electrically charged and their motion can be controlled using electric forces, ensuring they are collected and instead of being released into the atmosphere. ***Moving ions generated in gas discharges can also produce gas motion due to frequent collisions with neutral molecules this is commonly called the secondary electrohydrodynamic flow, or ionic wind. Moreover, the energy transfer from ions to gas molecules can locally increase their temperature producing a shock wave, which also affects the gas flow. The design and optimization of practical devices based on gas discharges require a thorough understanding of the process and ability to predict all electrical, chemical, thermal and aerodynamic characteristics of the process. ***The first objective of the proposed research program is to create a set of numerical algorithms, which can be used to simulate the corona, dielectric barrier and sliding discharges, assuming different parameters of the process: geometry of the discharge gap, polarity and waveform of the supplied voltage, and temperature, pressure and composition of ambient gas. Later, appropriate models can be used to study different devices, depending on the required accuracy and available computing resources. Commercial software packages are not able to solve this problem; they are usually divergent, or at least exhibit a large numerical diffusion. ***Having a reliable simulation tool, it will be possible to investigate and optimize three important practical devices: a gas discharge actuator for controlling the flow boundary layer, electrohydrodynamic dryers of organic substances, and electrostatic precipitators for submicron particles. A large percentage of power in Canada is generated by coal-fired power stations, which produce enormous amounts of dust. Efficient collection of this dust is of paramount importance for the health of our society, but also to protecting our environment. Improved characteristics of actuators for the boundary layer control can tremendously affect aircraft and wind turbine industries. **