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

工业、医药和环境保护中的许多过程都涉及气体中的放电。对于我们的社会来说，最重要的设备可能是静电除尘器，它可以去除许多工业过程中产生的灰尘颗粒，这样我们就可以呼吸更清洁的空气。许多有毒物质也可以用这种方法分解。这一切都是可能的，因为气体排放会产生自由离子和活性化学物质。灰尘颗粒可以带电，它们的运动可以用电力来控制，确保它们被收集起来，而不是被释放到大气中。

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.