Fuel density effect on near nozzle flow field in small laminar coflow diffusion flames
Type
ArticleAuthors
Xiong, Yuan
Cha, Min Suk

Chung, Suk Ho

KAUST Department
Clean Combustion Research CenterCombustion and Laser Diagnostics Laboratory
Mechanical Engineering Program
Physical Science and Engineering (PSE) Division
Date
2015Permanent link to this record
http://hdl.handle.net/10754/566114
Metadata
Show full item recordAbstract
Flow characteristics in small coflow diffusion flames were investigated with a particular focus on the near-nozzle region and on the buoyancy force exerted on fuels with densities lighter and heavier than air (methane, ethylene, propane, and n-butane). The flow-fields were visualized through the trajectories of seed particles. The particle image velocimetry technique was also adopted for quantitative velocity field measurements. The results showed that the buoyancy force exerted on the fuel as well as on burnt gas significantly distorted the near-nozzle flow-fields. In the fuels with densities heavier than air, recirculation zones were formed very close to the nozzle, emphasizing the importance of the relative density of the fuel to that of the air on the flow-field. Nozzle heating influenced the near-nozzle flow-field particularly among lighter fuels (methane and ethylene). Numerical simulations were also conducted, focusing specifically on the effect of specifying inlet boundary conditions for fuel. The results showed that a fuel inlet boundary with a fully developed velocity profile for cases with long tubes should be specified inside the fuel tube to permit satisfactory prediction of the flow-field. The calculated temperature fields also indicated the importance of the selection of the location of the inlet boundary, especially in testing various combustion models that include soot in small coflow diffusion flames. © 2014 The Combustion Institute.Citation
Xiong, Y., Cha, M. S., & Chung, S. H. (2015). Fuel density effect on near nozzle flow field in small laminar coflow diffusion flames. Proceedings of the Combustion Institute, 35(1), 873–880. doi:10.1016/j.proci.2014.06.025Publisher
Elsevier BVae974a485f413a2113503eed53cd6c53
10.1016/j.proci.2014.06.025