Effects of various densities and velocities on gaseous hydrocarbon fuel on near nozzle flow field under different laminar coflow diffusion flames Ngorn, Thou; Jang, Sehyun; Yun, Seok Hun; Park, Seol Hyeon; Lee, Joo Hee; Chung, Suk Ho; Choi, Jae Hyuk;
An experimental study on the flow characteristics under various laminar coflow diffusion flames was conducted with a particular focus on the buoyancy force exerted from gaseous hydrocarbon fuels. Methane (), ethylene (), and n-butane () were used as the fuels. A coflow burner and the Schlieren imaging technique were used to observe the flow field of each fuel near the nozzle exit as well as the flow characteristics in the flames. The results show that a vortex with a density heavier than air appeared in n-butane near the nozzle exit with a strong negative buoyancy on the fuel steam. As the Reynolds number increased through the control of the fuel velocity of the n-butane flame, the vortices were greater and the vortex tips were moved up from the nozzle exit. In addition, the heated nozzle affected the flow fields of the fuel steam near the nozzle exit.
J. H. Choi, "Experimental study on characteristics of synergistic effect of fuel mixing on number density and size of soot in ethylene-base counterflow diffusion flames by laser techniques," Journal of the Korean Society of Marine Engineering, vol. 33, no. 3, pp. 378-386, 2009.
J. H. Choi and S. K. Park, "A numerical study on soot formation in ethylene diffusion flame under 1g and 0g," Journal of the Korean Society of Marine Engineering, vol. 37, no. 8, pp. 807-815, 2013.
Y. Xiong, M. S. Cha, and S. H. Chung, "Fuel density effect on near nozzle flow field in small laminar coflow diffusion flames," Proceedings of the Combustion Institute, vol. 35, no. 1, pp. 873-880, 2015.
V. R. Katta and W. M. Roquemore, "Role of inner and outer structures in transitional jet diffusion flame," Combust and Flame 92, pp. 274-282, 1993.
R. W. Davis, E. F. Moore, W. M. Roquemore, L. D. Chen, V. Vilimpoc, and L. P. Goss, "Preliminary results of a numerical-experiment study of the dynamic structure of a buoyant jet diffusion flame," Combust and Flame 83, pp. 263-270, 1991.
J. Buckmaster and N. Peters, "The infinite candle and Its stability-A paradigm for flickering diffusion flames," Symposium (International) on Combustion, vol. 21, no. 1, pp. 1829-1836, 1988.
N. A. Eaves, A. Veshkini, C. Riese, Q. Zhang, S. B. Dworkin, and M. J. Thomson, "A numerical study of high pressure, laminar, sooting, ethylene-air coflow diffusion flames," Combust and Flame 159, pp. 3179-3190, 2012.
H. Gotoda, Y. Asano, K. H. Chuah, and G. Kushida, "Nonlinear analysis on Dynamic behavior of Buoyancy-Induced Flame Oscillation Under Swirling Flow," International Journal of Heat and Mass Transfer, vol. 52, no. 23-34, pp. 5423-5432, 2009.
D. Trees, T. M. Brown, K. Seshadri, M. D. Smooke, G. Balakrishnan, R. W. Pitz, V. Giovangigli, and S. P. Nandula, "The structure of nonpremixed hydrogen-air flames," Combustion Science and Technology, vol. 104, no. 4-6, pp. 427-439, 1995.
F. G. Roper, "The prediction of laminar jet diffusion flame sizes: Part I. theoretical model," Combust and Flame 29, pp. 219-234, 1977.
S. R. Turnes, An Introduction to Combustion Concepts and Applications, McGraw-Hill, USA, 1976.
M. R. J. Charest, C. P. T. Groth, and O .L. Gulder, "A numerical study on the effects of pressure and gravity in laminar ethylene diffusion flames," Combust and Flame 158, pp. 1933-1945, 2011.
M. A. Mikofski, T. C. williams, C. R. Shaddix, and L. G. Blevins, "Flame height measurement of laminar inverse diffusion flames," Combust and Flame 146, pp. 63-72, 2006.
O. L. Gulder, "Soot formation in laminar diffusion flames at elevated temperatures," Combust and Flame 88, pp. 74-82, 1992.
O. L. Gulder, "Influence of sulfur dioxide on soot formation in diffusion flames," Combusta and Flame 92, pp. 410-418, 1993.
O. L. Gulder, K. A. Thomson, and D. R. Snelling, "Effect of fuel nozzle material properties on soot formation and temperature field in coflow laminar diffusion flames," Combust and Flame 144, pp. 426-433, 2006.