Non-thermal and thermal plasma formation of radio-frequency dielectric barrier discharfe under high-pressure conditions

2017 Fiscal Year Final Research Report

• Project/Area Number: 16K14170
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Thermal engineering
• Research Institution: The University of Tokyo
• Principal Investigator: Tsue Mitsuhiro 東京大学, 大学院工学系研究科(工学部), 教授 (50227360)
• Co-Investigator(Renkei-kenkyūsha): NAKAYA SHINJI 東京大学, 大学院工学系研究科, 准教授 (00382234)
• Project Period (FY): 2016-04-01 – 2018-03-31
• Keywords: 非平衡プラズマ / 点火 / 燃焼 / 希薄混合気 / プラズマ反応 / 化学反応

Outline of Final Research Achievements

The ignition mechanism of non-thermal plasma formed by a radio-frequency dielectric barrier discharge was investigated for methane/air mixtures under high-pressure conditions. The minimum ignition energy was measured, and the plasma emissions were analyzed by spectrometers, considering the effects of the pressure and the frequency on the plasma formation. The results indicated that there was the minimal value of the minimum ignition energy against ambient pressure and the discharge frequency. An increase in the discharge frequency resulted in an enhancement of the active flame kernel formations although there might be active heat loss over a certain threshold of the frequency. At 500kPa, transitions from non-thermal to thermal plasmas were clearly observed in spectrograms measured with a high-speed imaging spectrometer. The effects of the frequency on the ignition performance was also validated by a chemical reaction analysis considering plasma and chemical reactions.

Free Research Field

燃焼工学