Transactions of the Korean Society of Mechanical Engineers B (대한기계학회논문집B)

The Korean Society of Mechanical Engineers (대한기계학회)
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Effect of Applied DC Electric Fields in Flame Spread over Polyethylene-Coated Electrical Wire

폴리에틸렌 피복전선 화염의 전파에 영향을 미치는 직류전기장의 인가 효과에 관한 실험적 연구

  • Jin, Young-Kyu (Dept. of Mechanical Engineering, Pukyong Nat'l Univ.) ;
  • Kim, Min-Kuk (Clean Combustion Research Center, King Abdullah University of Science and Technology.) ;
  • Park, Jeong (Dept. of Mechanical Engineering, Pukyong Nat'l Univ.) ;
  • Chung, Suk-Ho (Clean Combustion Research Center, King Abdullah University of Science and Technology.) ;
  • Yun, Jin-Han (Environmental & Energy Systems Research Division, Korea Institute of Machinery and Materials) ;
  • Keel, Sang-In (Environmental & Energy Systems Research Division, Korea Institute of Machinery and Materials)
  • Received : 2010.11.30
  • Accepted : 2010.12.22
  • Published : 2011.03.01
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Abstract

We experimentally investigated the effect of applied DC electric fields on the flame spread over polyethylene-coated electrical wire. The flame-spread rates over electrical wire with negative and positive DC electric fields from 0 to ${\pm}7$ kV were measured and analyzed. We compared the results for DC electric fields with previous results for AC electric fields. We explored whether or not various flame shapes could be obtained with DC electric fields and the main reason for the flame-spread acceleration, particularly at the end of the electrical wire, for AC electric fields. We found that DC electric fields do not significantly affect the flame-spread rates. However, the flame shape is mildly altered by the ionic wind effect even for DC electric fields. The flame-spread rate is relevant to the flame shape and the slanted direction in spite of the mild impact. A possible explanation for the flame spread is given by a thermal-balance mechanism and fuel-vapor jet.

본 연구는 전선화염의 전파특성에 직류전기장이 미치는 영향에 대한 실험적 연구이다. 화염전파는 은 0에서 ${\pm}7kV$ 범위의 음극과 양극의 전기장을 인가하여 실험되어졌다. 본 연구를 통해 앞선 전선화염 전파에 영향을 미치는 교류전기장 효과에 관한 연구결과와 비교하여 관찰된 다양한 화염 모양 변화의 원인을 알아보고, 화염 전파 속도의 가속특성에 대해서도 논의하고자 한다. 직류전기장의 인가가 전선화염에 미치는 영향은 크지 않지만 이온풍 효과에 따른 미미한 영향은 존재하며, 이것은 온도 균형 메커니즘과 연료 증발기체 분사 효과로 설명 될 수 있다.

Keywords

References

  1. Kikuchi, M., Fujita, O., Ito, K., Sato, A. and Sakuraya, T., 1998, “Experimental Study on Flame Spread over Wire Insulation in Microgravity," Proc. Combust. Inst., Vol 27, pp. 2507-2514 https://doi.org/10.1016/S0082-0784(98)80102-1
  2. Fujita, O., Nishizawa, K. and Ito, K., 2002, “Effect of Low External Flow on Flame Spread over Polyethylene-insulated Wire in Microgravity," Proc. Combust. Inst., Vol 29, pp. 2545-2552. https://doi.org/10.1016/S1540-7489(02)80310-8
  3. Kido, Y., Fujita, O., Kyono, T., Ito, H. and Nakamura, Y., 2009, “Observations of Wire Ignition Phenomena at Excess Electric Current Application in Reduced Gravity," 22nd ICDERS.
  4. Nakamura, Y., Yoshimura, N., Ito, H., Azumaya, K. and Fujita, O., 2009, “Flame Spread over Electric Wire in Sub-atmospheric Pressure," Proc. Combust. Inst., Vol 32, pp. 2559-2566. https://doi.org/10.1016/j.proci.2008.06.146
  5. Onishi, Y., Fujita, O., Agata, K., Takeuchi, H., Nakamura, Y., Ito, H. and Kikuchi, M., 2010, “Observation of Flame Spreading over Electric Wire under Reduced Gravity Condition Given by Parabolic Flight and Drop Tower Experiments," Trans. JSASS Space Tech.Japan.
  6. Kim, M. K., SChung, . H. and Fujita, O., 2010, “Effect of AC electric fields on flame spread over electrical wire," Proc. Combust. Inst., Article in press.
  7. Kono, M., Iinuma, K. and Kumagai, S., 1981, “The Effect of DC to 10 MHz Electric Field on Flame Luminosity and Carbon Formation," Proc. Combust. Inst., Vol 18, pp. 1167-1174. https://doi.org/10.1016/S0082-0784(81)80121-X
  8. Won, S. H., Ryu, S. K., Kim, M. K., Cha, M. S. and Chung, S. H., 2008, “Effect of Electric Fields on the Propagation Speed of Tribrachial Flames in Coflow Jets," Combust. Flame, Vol. 152, pp. 496-506. https://doi.org/10.1016/j.combustflame.2007.11.008
  9. Kim, H. H., Kim, M. K. and Chung, S. H., 2010, “Effect of DC Electric Fields on the Stabilization of Premixed Bunsen Flame," KOSCO Symposium, Vol 40, pp. 53-59.
  10. Jin, Y. K., Kim, M. K., Park, J., Chung, S. H., Kwon, O. B. and Bae, D. S., 2010, “Experimental Study on the Characteristics of Flame Spread in Polyethylene-insulated Electric-Wire with AC Electric Fields," KOSCO Symposium, Vol 40, pp. 25-37.
  11. Lawton, J. and Weinberg, F., 1969, “Electrical Aspects of Combustion," Clarendon Press.
  12. Place, E. R. and Weinberg, F. J., “Electrical Control of Flame Carbon” Proc. Roy. Soc.(London), Vol. A289, pp. 192-205.
  13. Heinsohn, R. J., Wulfhorst, D. E. and Becker, P. M., 1967, “The Effects of an Electric Field on an Oppsed-jet Diffusion Flame," Combust. Flame, Vol 11, pp. 288-296. https://doi.org/10.1016/0010-2180(67)90018-1
  14. Nakamura, Y., Yoshimura, N., Matsumura, T., Ito, H., Fujita, O., 2008, “Opposed-wind Effect on Flame Spread of Electric Wire in Sub-atmospheric Pressure," JTST, Vol 3, pp. 430-441. https://doi.org/10.1299/jtst.3.430
  15. Mayo, P. J., Weinberg, F. J., “On the Size, Charge, and Number-Rate of Formation of Carbon Particles in Flames Subjected to Electric Fields” Proc. Roy. Soc.(London), Vol. A319, pp. 351-371.
  16. Bradley, D., The Effect of Electric Fields on Combustion Processes, Edited by F. J. Weinberg, Chap. 6 of Advanced Combustion Methods, Academic Press.
  17. Kobayashi, H., Park, J., Iwahashi, T. and Niioka, T., 2002, “Microgravity Experiments on Flame Spread Of n-Decane Droplet Array in a High-Pressure Environment," Proc. Combust. Inst., Vol 29, pp. 2603-2610. https://doi.org/10.1016/S1540-7489(02)80317-0

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