Study of Plasma Phenomena at High Electric Fields in Applications for Active Flow Control and Ultra-short Pulse Laser Drilling PDF Download

Author: Alexandre Likhanskii
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Languages : en
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Book Description
Plasma engineering is one of the most actively growing research areas in modern science. Over the past decade, plasma engineering became a significant part of aerospace engineering, material processing, medicine, geosciences, etc. One of the main goals of plasma research is to discover new perspectives in a wide range of research areas. It makes plasma engineering a truly interdisciplinary subject. Recently, a significant interest in the aerospace community was caused by the possibility of an active flow control using dielectric barrier discharge (DBD) plasma actuators. A number of groups tried to explain the physics of the experimentally observed phenomena. However, the developed models could hardly explain the DBD phenomena even qualitatively. This thesis presents the first complete, comprehensive, physically-based model, which tracks all essential physics of the DBD plasma actuators and utilizes modern numerical capabilities for efficient simulations. By using the developed model, the physics of the plasma actuators was explained. Based on the understanding of the operation of the conventional DBD, driven by a sinusoidal voltage, a novel configuration was proposed. The sinusoidal driving voltage was substituted by the repetitive nanosecond pulses superimposed on the bias voltage. The advantages of the proposed concept over the conventional one were experimentally validated. The developed model demonstrated flexibility for different plasma engineering areas. The model can be used not only for a description of the DBD plasma actuators, but also for a number of problems involving the gas discharges. By using the developed model, plasma generation by the ferroelectric plasma source, which is used in fusion technology, was explained. In the area of material processing, a significant interest was caused by an apparent possibility of precise high intensity ultra-short laser pulse drilling with negligible melt production. However, the experiments did not validate the theories proposed in literature. In order to explain the experimental data and analyze the possibility of reduction of melt generation, a new model for laser pulse drilling was developed in this thesis. The model comprehensively describes laser-material interaction and explains the significant amount of melt production in the case of ultra-short laser pulses. The results of the simulations are in good agreement with the experimental data.