Combustion behavior of three different fuel droplets in vertical electric field under gravity
Chaogang FANG,Qiang SONG,Lei ZHONG,Gang XIONG,Qiang YAO
Key Laboratory of Thermal Science and Power Engineering of Ministry of Education,Department of Thermal Engineering, Tsinghua University, Beijing 100084, China
Propanol, n-decane, and diesel droplets were selected as experimental samples to study combustion behavior of fuel droplets in a vertical electric field under gravity. A high speed camera was used to measure the combustion flame and droplet size, with laser-induced incandescence (LII) applied to determining soot volume fractions. The results show that the flame height of each fuel increases with increasing electrodes voltage, while the flame width decreases with increasing electrodes voltage. Propanol droplet combustion does not produce soot, with n-decane and diesel flame soot volume fraction decreasing with increasing electrodes voltage. Burning rate constants increase with increasing electrodes voltage with the maximum burning rate constant increasing by 9%, 20%, and 30% for propanol, decane, and diesel, respectively. Analyses show that electric field stretching on the flame induces soot formation suppression and promotes soot oxidation, reducing soot generation and weakening soot external radiation heat transfer, so as to promote fuel combustion.
方朝纲, 宋蔷, 仲蕾, 熊刚, 姚强. 重力场作用下三种不同燃料液滴在垂直电场中的燃烧特性[J]. 清华大学学报（自然科学版）, 2014, 54(1): 97-101.
Chaogang FANG, Qiang SONG, Lei ZHONG, Gang XIONG, Qiang YAO. Combustion behavior of three different fuel droplets in vertical electric field under gravity. Journal of Tsinghua University(Science and Technology), 2014, 54(1): 97-101.
Bradley D. The effect of electric fields on combustion process [M]//Advanced Combustion Methods. London: Academic Press, 1986.
[2]
Lawton J, Weinberg F J. Electrical aspects of combustion [M]. Oxford: Clarendon Press, 1969.
[3]
Saito M, Sato M, Sawada K. Variation of flame shape and soot emission by applying electric field [J]. Journal of Electrostatics, 1997, 39(4): 305-311.
[4]
van den Boom J D B J, Konnov A A, Verhasselt A M H H, et al. The effect of a DC electric field on the laminar burning velocity of premixed methane/air flames[J]. Proceedings of the Combustion Institute, 2009, 32(1): 1237-1244.
[5]
Wang Y, Nathan G J, Alwahabi Z T, et al.Effect of a uniform electric field on soot in laminar premixed ethylene/air flames[J]. Combustion and Flame, 2010, 157(7): 1308-1315.
[6]
Saito M, Arai T, Arai M. Control of soot emitted from acetylene diffusion flames by applying an electric field[J]. Combustion and Flame, 1999, 119(3): 356-366.
[7]
Vega E V, Sung S S, Lee K Y. NO emission of oxygen-enriched CH4/O2/N2 premixed flames under electric field[J]. Fuel, 2007, 86(4): 512-519.
[8]
Imamura O, Kubo Y, Osaka J,et al.A study on single fuel droplets combustion in vertical direct current electric fields[J]. Proceedings of the Combustion Institute, 2005, 30(2): 1949-1956.
[9]
Imamura O, Kubo Y, Osaka J, et al.Observation of sooting behavior in single droplets in combustion in direct current electric fields under microgravity[J]. Microgravity Science and Technology, 2005, 17(1): 13-17.
[10]
Choi M Y, Lee K O. Investigation of sooting in microgravity droplet combustion[J]. Symposium (International) on Combustion, 1996, 26(1): 1243-1249.
[11]
Okai K, Moriue O, ArakiI M, et al. Combustion of single droplets and droplet pairs in a vibrating field under microgravity[J]. Proceedings of the Combustion Institute, 2000, 28(1): 977-983.
[12]
Belhi M,Domingo P, Vervisch P. Direct numerical simulation of the effect of an electric field on flame stability[J]. Combustion and Flame, 2010, 157(12): 2286-2297.
[13]
Chang K C, Shieh J S. Theoretical investigation of transient droplet combustion by considering flame radiation[J]. International Journal of Mass and Heat Transfer, 1995, 38(14): 2611-2621.
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