外界风对射流扩散火焰图像特征的影响
|
摘要
以丙烷为研究对象,通过在燃烧风洞建立射流火实验平台,研究外界风对射流火焰形态、平均火焰长度、平均倾斜角度等火焰图像特征的影响.实验获得了不同外界风速下丙烷射流火焰形态特征,对比分析了不同动量通量比R下的火焰形态.结果表明,R越大,火焰下洗程度越不明显,直至消失;在一定风速范围内,随着外界风速增大,平均火焰长度增加,平均火焰倾斜角度增加;结合实验数据,在理论模型的基础上,发展出无量纲火焰长度与外界风速、射流出口速度之间的关系;应用类比思想,提出了平均火焰倾斜角度与外界风弗劳德数、燃料射流间的关系.
A series of experiments were carried out in a wind tunnel to study the effect of cross-wind on the image characteristics of propane gas jet diffusion flame,such as flame shape,mean flame length and mean flame tilt angle.Analysis of propane jet flame shape in different cross-wind speeds shows that flame shape depends on the momentum flux ratio of fuel jet to cross-wind(R). The larger R is,the less obvious emerging down-wash of flame shape will be until it disappears. Experimental data indicates that within a range of wind speed,as wind speed increases,the mean flame length increases,and the mean flame tilt angle also increases. In combination with the experimental data,the relationship between dimensionless flame length and cross-wind speed and jet exit velocity is obtained on the basis of the theoretical model. Applying analogy thought,further investigation is required to research the relationship between mean flame tilt angle and Frode number(Frw,Frj).
A series of experiments were carried out in a wind tunnel to study the effect of cross-wind on the image characteristics of propane gas jet diffusion flame,such as flame shape,mean flame length and mean flame tilt angle.Analysis of propane jet flame shape in different cross-wind speeds shows that flame shape depends on the momentum flux ratio of fuel jet to cross-wind(R). The larger R is,the less obvious emerging down-wash of flame shape will be until it disappears. Experimental data indicates that within a range of wind speed,as wind speed increases,the mean flame length increases,and the mean flame tilt angle also increases. In combination with the experimental data,the relationship between dimensionless flame length and cross-wind speed and jet exit velocity is obtained on the basis of the theoretical model. Applying analogy thought,further investigation is required to research the relationship between mean flame tilt angle and Frode number(Frw,Frj).
引文
[1]Majeski A J,Wilson D J,Kostuik L W.Size and trajectory of a flare in a cross flow[C]//Combustion Canada.Calgary Alberta,1999.
[2]王大庆,高惠临,霍春勇,等.天然气管道泄漏射流火焰形貌研究[J].油气储运,2006,25(2):47-49.Wang Daqing,Gao Huilin,Huo Chunyong,et al.Study on the jet-fire shapes of gas pipeline[J].Oil&Gas Storage and Transportation,2006,25(2):47-49(in Chinese).
[3]Kalghatgi G T.The visible shape and size of a turbulent hydrocarbon jet diffusion flame in a cross-wind[J].Combustion and Flame,1983,52:91-106.
[4]Huang R F,Chang J M.Coherent structure in a com busting jet in crossflow[J].AIAA Journal,1994,32(6):1120-1125.
[5]Huang R F,Chang J M.The stability and visualized flame and flow structures of a combusting jet in cross flow[J].Combustion and Flame,1994,98(3):267-278.
[6]Huang R F,Wang S M.Characteristic flow modes of wake-stabilized jet flames in a transverse air stream[J].Combustion and Flame,1999,117(1):59-77.
[7]Majeski A J.Size and Shape of Low Momentum Jet Diffusion Flames in Cross Blow[D].Alberta:University of Alberta,2000.
[8]Majeski A J,Wilson D J,Kostiuk L W.Predicting the length of low-momentum jet diffusion flames in crossflow[J].Combustion Science and Technology,2004,176(12):2001-2025.
[9]Johnson M R,Kostiuk L W.Efficiencies of lowmomentum jet diffusion flames in crosswinds[J].Combustion and Flame,2000,123(1):189-200.
[10]周建军,余彪,严明,等.燃烧风洞的研制及其燃烧特性研究[J].火灾科学,1994,3(2):35-43.Zhou Jianjun,Yu Biao,Yan Ming,et al.Manufacture of combustion wind tunnel and research on combustibles combustion characteristic[J].Fire Safety Science,1994,3(2):35-43(in Chinese).
[11]Turns S R.An Introduction to Combustion:Concepts and Applications[M].2nd ed.US:The Mc Graw-Hill Companies,2000.
[12]陈志斌,胡隆华,霍然,等.基于图像亮度统计分析火焰高度特征[J].燃烧科学与技术,2008,14(6):557-561.Chen Zhibin,Hu Longhua,Huo Ran,et al.Flame height characteristics based on image luminance[J].Journal of Combustion Science and Technology,2008,14(6):557-561(in Chinese).
[13]Oka Y,Sugawa O,Imamura T,et al.Effects of crosswinds to apparent flame height and tilt angle from several kinds of fire source[C]//Proceedings of the 7th International Symposium on Fire,International Association of Fire Safety and Science.Worcester,USA,2002:915-926.
[14]Karlsson B,Quintiere J.Enclosure Fire Dynamics[M].Florida:CRC press,2002.
[2]王大庆,高惠临,霍春勇,等.天然气管道泄漏射流火焰形貌研究[J].油气储运,2006,25(2):47-49.Wang Daqing,Gao Huilin,Huo Chunyong,et al.Study on the jet-fire shapes of gas pipeline[J].Oil&Gas Storage and Transportation,2006,25(2):47-49(in Chinese).
[3]Kalghatgi G T.The visible shape and size of a turbulent hydrocarbon jet diffusion flame in a cross-wind[J].Combustion and Flame,1983,52:91-106.
[4]Huang R F,Chang J M.Coherent structure in a com busting jet in crossflow[J].AIAA Journal,1994,32(6):1120-1125.
[5]Huang R F,Chang J M.The stability and visualized flame and flow structures of a combusting jet in cross flow[J].Combustion and Flame,1994,98(3):267-278.
[6]Huang R F,Wang S M.Characteristic flow modes of wake-stabilized jet flames in a transverse air stream[J].Combustion and Flame,1999,117(1):59-77.
[7]Majeski A J.Size and Shape of Low Momentum Jet Diffusion Flames in Cross Blow[D].Alberta:University of Alberta,2000.
[8]Majeski A J,Wilson D J,Kostiuk L W.Predicting the length of low-momentum jet diffusion flames in crossflow[J].Combustion Science and Technology,2004,176(12):2001-2025.
[9]Johnson M R,Kostiuk L W.Efficiencies of lowmomentum jet diffusion flames in crosswinds[J].Combustion and Flame,2000,123(1):189-200.
[10]周建军,余彪,严明,等.燃烧风洞的研制及其燃烧特性研究[J].火灾科学,1994,3(2):35-43.Zhou Jianjun,Yu Biao,Yan Ming,et al.Manufacture of combustion wind tunnel and research on combustibles combustion characteristic[J].Fire Safety Science,1994,3(2):35-43(in Chinese).
[11]Turns S R.An Introduction to Combustion:Concepts and Applications[M].2nd ed.US:The Mc Graw-Hill Companies,2000.
[12]陈志斌,胡隆华,霍然,等.基于图像亮度统计分析火焰高度特征[J].燃烧科学与技术,2008,14(6):557-561.Chen Zhibin,Hu Longhua,Huo Ran,et al.Flame height characteristics based on image luminance[J].Journal of Combustion Science and Technology,2008,14(6):557-561(in Chinese).
[13]Oka Y,Sugawa O,Imamura T,et al.Effects of crosswinds to apparent flame height and tilt angle from several kinds of fire source[C]//Proceedings of the 7th International Symposium on Fire,International Association of Fire Safety and Science.Worcester,USA,2002:915-926.
[14]Karlsson B,Quintiere J.Enclosure Fire Dynamics[M].Florida:CRC press,2002.