Measurements of velocity and fuel concentration in the stabilization region of lifted jet diffusion flames

✍ Scribed by Lester K. Su; Donghee Han; M.G. Mungal

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 244 KB
• Volume: 28
• Category: Article
• ISSN: 1540-7489
• DOI: 10.1016/s0082-0784(00)80227-1

✦ Synopsis

Simultaneous particle image velocimetry (PIV) and planar laser-induced fluorescence (PLIF) yield measurements of velocity and fuel mole fraction in the stabilization region of lifted, turbulent coflowing methane jet diffusion flames. The measurements supplement previous studies of turbulent jet flame stabilization, in which velocities were measured simultaneously with combustion radicals used to mark reaction zones. The present results indicate that fuel concentrations at the most upstream points of observed high-temperature interfaces, and to the outside of these points, are rarely high enough to support combustion. Rather, combustion appears to occur primarily on the portions of these interfaces nearer the jet centerline, consistent with previous PLIF results for CH and OH radical concentrations. Measured axial velocities upstream are on the order of the laminar flame speed, S L , in agreement with previous PIV measurements showing the tendency of the flame to stabilize in low velocity regions, and consistent with simulations of idealized leading-edge flames. Radial profiles of axial velocity and fuel fraction immediately upstream of these high-temperature interfaces lend further support to the notion that the upstream portion of a lifted turbulent jet flame can be described as a leading-edge flame interacting with incoming vortical structures.