Seminars

The goal of the present work is the study of high pressure non-equilibrium plasma discharges in chemically reactive systems. In this work, we present coupled computational studies of high pressure nanosecond pulsed plasmas for multiphysics applications ranging from plasma assisted combustion ignition, large gap thermal breakdown, to electric discharge in liquids for fuel reforming and biomedical applications.

In the first part of the work, a coupled two-dimensional computational model of nanosecond pulsed plasma induced flame ignition and combustion for a lean H2-air mixture in a high pressure environment is described. The model provides a full fidelity description of plasma formation, combustion ignition, and flame development. We study the effect of three important plasma properties that influence combustion ignition and flame propagation, namely a) plasma gas temperature, b) plasma-produced primary combustion radicals O,OH, and H densities, and c) plasma-generated charged and electronically excited radical densities.

In the second part of the work, we present a computational study of nanosecond streamer discharges in helium gas bubbles suspended in distilled water for liquid reforming and biomedical applications. The objective is to study the kinetics and dynamics of streamer evolution and maximize active species production within the gas bubbles which is the quantity of interest for plasma processing of liquids. We investigate two parameters, namely a) trigger voltage polarity and b) presence of multiple bubbles which are found to significantly influence the characteristics of the discharge in gas bubbles.

In the final part of the work, we report the results of a computational study which explores argon surface streamers as a low-voltage mechanism for thermal breakdown of large interelectrode gaps and investigate the effect of impurities (O₂) on the development of continuous surface streamer channels under atmospheric-pressure conditions.