Wookyung Kim

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—The authors examine three different types of plasma discharges in their ability to stabilize a lifted jet diffusion flame in coflow. The three discharges include a single-electrode corona discharge, an asymmetric dielectric-barrier discharge (DBD), and a repetitive ultrashort-pulsed discharge. The degree of nonequi-librium of this pulsed discharge is found(More)
A pulsed plasma source is used to stabilize lean premixed methane flames. Nitric oxide (NO) production is measured using probe sampling and chemiluminescence analysis. While the discharge is a potential source of NO, it is observed that the flame also consumes some NO. The NO production in the flame is modeled by use of a modified opposed diffusion flame(More)
Repetitively pulsed, nonequilibrium plasma discharges are studied for their ability to ignite and stabilize methane jet flames in cross flow air. The placement of the discharge is surveyed to optimize the flame duty cycle (stability). We find that flame ignition is not achieved when the discharge is located in the potential core region of the fuel jet or on(More)
Phase-locked particle image velocimetry is used to study the mechanism of induced flow in the near field of a rf dielectric barrier discharge actuator mounted in the separated flow region of a bluff body. Flow actuation is found to be asymmetric, with suction toward the buried downstream electrode when it is biased positively relative to the upstream(More)
This paper examines the use of plasma discharges in flame stabilization. Three different types of plasma discharges are applied to a lifted jet diffusion flame in a coflow configuration, and evaluated for their abilities to enhance flame stabilization. A single electrode corona discharge (SECD) between a platinum electrode and the flame base is found to(More)
This paper describes a mechanism for the stabilization of ultra lean premixed methane/air flames by pulsed nonequilibrium plasma enhancement. It is shown that the pulsed discharge plasma produces a cool ($500–600 K) stream of relatively stable intermediate species including hydrogen (H 2) and carbon monoxide (CO), which play a central role in enhancing(More)
—We report on a study of the use of repetitive ultra-short pulsed plasma discharges in stabilizing a lifted methane jet diffusion flame in elevated temperature (855 K–975 K) vitiated coflow. CH chemiluminescence images are used to record the flame liftoff height, which serves as a measure of the flame stability. The results show that, for the same reduced(More)
Surface dielectric barrier discharges (DBDs) are used to delay flow separation behind a bluff body in atmospheric pressure air. The bluff body is made by connecting a flat plate to a half cylinder tangentially as a round-cornered trailing edge. Four DBD plasma actuators are attached along the surface of the half cylinder. Particle Image Velocimetry (PIV) is(More)
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