本研究之目的為針對火焰於微管內傳遞動態進行實驗解析。實驗方法為於透明微管中央點火，利用高速顯影紀錄管內火焰傳遞動態並據以歸納分類。實驗所探討之影響參數包括管徑、當量比以及燃料種類。
研究結果首先發現乙烯/氧氣火焰於化學當量比條件下可於3 mm至0.4 mm I.D.之微管內觀察到DDT/C-J模式。隨當量比改變，管徑1 mm、2 mm與3 mm I.D.微管中有由緩燃焰轉震爆焰而後以Chapman-Jouguet(C-J)速度傳遞之DDT/C-J模式、穩定緩燃焰傳遞、震盪火焰與點火後傳遞一段距離即熄焰四種。在管徑0.5 mm I.D.中，於當量比偏貧油區域，則有跳躍式火焰傳遞模態。管徑0.4 mm I.D.則觀察到低速爆震焰、近似爆震焰以及DDT/C-J傳遞三種模態。由管徑與當量比之組合，DDT/C-J模式存在的當量比區間以及緩燃焰傳遞的可燃區間隨著管徑縮小而減少。在1 mm、2 mm與3 mm I.D. 微管中傳遞速度量值與C-J速度相比無顯著損耗。在管徑0.5 mm以及0.4 mm I.D.的微管中，則出現約5%及10％的速度損耗。
針對甲烷/氧氣火焰傳遞，我們也觀察到化學當量比條件下於2 mm與3 mm I.D.微管內為DDT/C-J模式。於1.5 mm I.D.中則發現火焰加速達DDT階段後持續減速至出口之爆震焰減速以及近似爆震焰與延遲爆震焰傳遞三種模式。在1 mm管徑之平滑直管中則是以緩燃焰方式傳遞。進一步針對管徑與當量比變化可得傳遞模式分佈圖。穩定爆震焰傳遞存在的當量比區間範圍，同樣隨著管徑縮小而減少。緩燃焰傳遞極限區間則是隨管徑縮小而增寬。

The objective of the present research was to experimentally analyze flame propagation modes in micro scale tubes. The reaction propagations of premixed ethylene/oxygen and methane/oxygen mixtures in capillary tubes were investigated. Evolutions of flame structures and velocity deficits were also experimentally characterized.
Results show that the propagation mode of ethylene/oxygen was influenced by equivalence ratio and tube diameter. For ethylene/oxygen mixtures in 1 mm, 2 mm and 3 mm I.D. tubes, deflagration, oscillating flame, DDT/C-J and reaction quench propagation modes were identified for equivalence ratios from lean to rich. In 0.5 mm I.D. tubes, a galloping detonation mode was observed at fuel-lean equivalence ratios in addition to DDT/C-J mode. In 0.4 mm I.D. tubes, low speed detonation, quasi-detonation and DDT/C-J modes were observed for equivalence ratios from lean to rich. The equivalence ratio range of DDT/C-J mode and deflagration limits shrinks with decreasing tube diameter. Velocity deficit was not observed for 1 mm, 2 mm and 3 mm I.D. tubes, but 5% and 10% deficit was found in the 0.5 mm and 0.4 mm I.D.
There were deflagration, oscillating flame and DDT/C-J modes for methane/oxygen flames in 2 mm and 3 mm I.D. tubes; however, the DDT/C-J mode is replaced by DDT/deceleration, quasi-detonation and long-delay detonation mode in 1.5 mm I.D. tube. In 1 mm I.D. tubes, only steady deflagration-quench mode was observed. The equivalence ratio range of DDT/C-J mode shrinks with decreasing tube diameter. The equivalence ratio range of deflagration limits expands with decreasing tube diameter.

參考文獻

[1] M.H. Wu, M.P. Burke, S.F. Son and R.A. Yetter (2007), Flame acceleration and the transition to detonation of stoichiometric ethylene/oxygen in microscale tubes, Proceedings of the Combustion Institute 31(2), 2429-2436.
[2] K. Ishii, K. Itoh and T. Tsuboi (2003), A study on velocity deficits of detonation waves in narrow gaps, Proceedings of the Combustion Institute 29, 2789-2794.
[3] S. Kitano, M. Fukao, A. Susa, N. Tsuboi, A.K. Hayashi and M. Koshi (2009), Spinning detonation and velocity deficit in small diameter tubes, Proceedings of the Combustion Institute 32, 2355-2362.
[4] P.A. Urtiew and A.K. Oppenheim (1966), Experimental observations of the transition to detonation in an explosive gas, Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences 295(1440), 13-28.
[5] K. Ishii and H. Gronig (1998), Behavior of detonation waves at low pressures, Shock Waves 8(1), 55-61.
[6] S.M. Frolov and B.E. Gel'fand (1991), Limit diameter of gas detonation propagation in tubes, Combustion, Explosion, and Shock Waves 27(1), 113-117.
[7] L.E. Bollinger, G.C. Smith, F.J. Tomazic and R. Edse (1966), Formation of detonation waves in flowing hydrogen-oxygen and methane-oxygen mixtures, AIAA Journal 4(10), 1773-1776.
[8] W. Pusch and H.G. Wagner (1962), Investigation of the dependence of the limits of detonatability on tube diameter, Combustion and Flame 6, 157-162.
[9] V.I. Manzhalei (1992), Low-velocity gas detonation in capillaries, Doklady Akademii Nauk 324(3), 582-584.
[10] V.I. Manzhalei (1992), Detonation Regimes of Gases in Capillaries, Combustion Explosion and Shock Waves 28(3), 296-302.
[11] V.I. Manzhalei (1999), Low-velocity detonation limits of gaseous mixtures, Combustion Explosion and Shock Waves 35(3), 296-302.
[12] I.O. Moen, M. Donato, R. Knystautas and J.H. Lee (1980), Flame acceleration due to turbulence produced by obstacles, Combustion and Flame 39(1), 21-32.
[13] M. Kuznetsov, V. Alekseev, Y. Yankin and S. Dorofeev (2002), Slow and fast deflagrations in hydrocarbon–air mixtures, Combustion Science and Technology 174(5), 157 - 172.
[14] A. Teodorczyk (2008), Scale effects on hydrogen-air fast deflagrations and detonations in small obstructed channels, Journal of Loss Prevention in the Process Industries 21(2), 147-153.
[15] A. Teodorczyk, P. Drobniak and A. Dabkowski (2009), Fast turbulent deflagration and DDT of hydrogen-air mixtures in small obstructed channel, International Journal of Hydrogen Energy 34(14), 5887-5893.
[16] I. Brailovsky, M. Frankel and G. Sivashinsky (2000), Galloping and spinning modes of subsonic detonation, Combustion Theory and Modelling 4(1), 47-60.
[17] J.D. Ott, E.S. Oran and J.D. Anderson (2003), A mechanism for flame acceleration in narrow tubes, AIAA Journal 41(7), 1391-1396.
[18] J. Daou and M. Matalon (2002), Influence of conductive heat-losses on the propagation of premixed flames in channels, Combustion and Flame 128(4), 321-339.
[19] V. Bychkov, V. Akkerman, G. Fru, A. Petchenko and L.E. Eriksson (2007), Flame acceleration in the early stages of burning in tubes, Combustion and Flame 150(4), 263-276.
[20] C.K. Law (2006), Combustion Physics, Cambridge University Press, New Jersey.
[21] Z.B. Song, X.W. Ding, J.L. Yu and Y.Z. Chen (2006), Propagation and quenching of premixed flames in narrow channels, Combustion Explosion and Shock Waves 42(3), 268-276.
[22] K. Nagai, T. Okabe, K. Kim, T. Yoshihashi, T. Obara and S. Ohyagi (2009), A study on DDT processes in a narrow channel, 26th International Symposium on Shock Waves 1, 203-208.
[23] L. Kagan and G. Sivashinsky (2003), The transition from deflagration to detonation in thin channels, Combustion and Flame 134(4), 389-397.
[24] V. Bychkov, A. Petchenko, V. Akkerman and L.E. Eriksson (2005), Theory and modeling of accelerating flames in tubes, Physical Review E 72(4), 1539-3755.
[25] I. Brailovsky and G.I. Sivashinsky (2000), Hydraulic resistance as a mechanism for deflagration-to-detonation transition, Combustion and Flame 122(4), 492-499.
[26] L. Kagan and G. Sivashinsky (2008), Autoignition due to hydraulic resistance and deflagration-to-detonation transition, Combustion and Flame 154(1-2), 186-190.
[27] L. Kagan and G. Sivashinsky (2010), On the Transition from Deflagration to Detonation in Narrow Tubes, Flow, Turbulence and Combustion 84(3), 423-437.
[28] Y.B. Zeldovich (1950), On the theory of the propagation of detonation in gaseous systems, Journal of Experimental and Theoretical Physics 10, 542-568.
[29] G.B. Kistiakowsky, H. Knight and M. Malin (1952), Gaseous detonations. V. nonsteady waves in CO-O2 mixtures, Journal of Chemical Physics 20(6).
[30] J.A. Fay (1959), Two‐dimensional gaseousdetonations: Velocity deficit, Physics of Fluids 2, 283-289.
[31] M.H. Wu (2007), Development and experimental analyses of meso and micro scale combustion systems, Ph.D. Dissertation, Pennsylvania State University.
[32] D. Goodwin, Cantera: Object-oriented software for reacting flows, Version 1.7, http://www.cantera.org.
[33] S. Gordon and B.J. McBride (1994), Computer program for calculation of complex chemical equilibrium compositions and applications, NASA Reference Publication No. 1311.
[34] J. Jarosinski (2009), Combustion Phenomena: Selected Mechanisms of Flame Formation, Propagation and Extinction, CRC Press.
[35] A. Eder, F. Pintgen and F. Mayinger (2000), Experimental observation of fast deflagrations and transition to detonations, Proceedings of Symposium on Energy Engineering in the 21st Century 3, S. 1296ff, Begell House, New York.
[36] G.O. Thomas (2009), Flame acceleration and the development of detonation in fuel-oxygen mixtures at elevated temperatures and pressures, Journal of Hazardous Materials 163(2-3), 783-794.
[37] H. Steen and K. Schampel (1983), Experimental investigation of the run-up distance of gaseous detonations in large pipes, 4th International Symposium on Loss Prevention and Safety Promotion in the Process Industries,Pergamon Press ,London UK, E23-E33.
[38] K. Aizawa, S. Yoshino, T. Mogi, H. Shiina, Y. Ogata, Y. Wada and A. Hayashi (2008), Study of detonation initiation in hydrogen/air flow, Shock Waves 18(4), 299-305.
[39] J. Li, W. Lai and K. Chung (2006), Tube diameter effect on deflagration-to-detonation transition of propane–oxygen mixtures, Shock Waves 16(2), 109-117.
[40] N. Manson and H. Guénoche (1957), Effect of the charge diameter on the velocity of detonation waves in gas mixtures, Symposium (International) on Combustion 6(1), 631-639.
[41] A. Vasil’ev (2008), Quasi-steady regimes of wave propagation in active mixtures, Shock Waves 18(4), 245-253.