This study explores the used of nanosecond-pulsed high-frequency discharge (NPHFD) plasma for ignition of flowing mixtures, relevant for gas turbine and advanced high-speed engines such ramjets and scramjets. This work is a collaborative effort with the US Air Force Research Laboratory, and is supported by grants from the Israel Science Foundation and MAFAT.
The use of plasma discharges, such as NPHFD, have been shown to be able to increase ignition probability while reducing energy consumption compared to standard capacitive or inductive ignition sources. By tailoring the discharge power, total energy, and duration an optimal discharge for a given flow environment can be found. This is due to the ability to control the power addition rate using discrete discharges and the phenomena of “inter-pulse coupling” in which multiple discrete pulsed discharges combine to form a quasi-continuous discharge region at a controllable average power level. This allows fine-tuned control of ignition probability as well as early kernel expansion rates.
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- Simultaneous OH-PLIF and schlieren imaging at 50 kfps
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- Ignition probability map of a methane air mixture with 0.6 equivalence ratio and u=10 m/s
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- Ignition kernel imaging as a function of pulse frequency for a methane-air mixture at 0.6 equivalence ratio and u=10 m/s
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- Measure vs. predicted ignition kernel area at the end of a NPHFD pulse train
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- Diagram of ignition kernel growth