Microgravity diffusion flame spread over a thick solid in step-changed low-velocity opposed flows

2019 ◽  
Vol 205 ◽  
pp. 55-67 ◽  
Author(s):  
Feng Zhu ◽  
Zhanbin Lu ◽  
Shuangfeng Wang ◽  
Yongli Yin
Keyword(s):  
Flame Spread ◽  
Diffusion Flame ◽  
Low Velocity

Structure of the Stabilizing Region of a Laminar Jet Diffusion Flame

1988 ◽  
Vol 110 (1) ◽  
pp. 182-189 ◽  
Author(s):  
F. Takahashi ◽  
M. Mizomoto ◽  
S. Ikai
Keyword(s):  
Diffusion Flame ◽  
Diffusion Flames ◽  
Back Diffusion ◽  
Velocity Data ◽  
Base Region ◽  
Flame Zone ◽  
Low Velocity ◽  
Laminar Jet ◽  
Major Species ◽  
Dark Space

Velocity, temperature, and composition of major species were measured in the base region of a two-dimensional, laminar methane jet diffusion flame in unconfined still air under a low-velocity jetting condition. The velocity data showed acceleration near the flame zone caused primarily by thermal expansion and buoyancy. The heat flux vectors showed substantial heat flow from the flame base to both downstream and the burner wall. The premixed zone was formed in the dark space by convective penetration of oxygen and back-diffusion of methane. The molar flux vectors of methane and oxygen at the base pointed to the opposite directions, typical of diffusion flames.

Motions of neutral hydrogen at high latitudes

1967 ◽  
Vol 31 ◽  
pp. 265-278 ◽  
Author(s):  
A. Blaauw ◽  
I. Fejes ◽  
C. R. Tolbert ◽  
A. N. M. Hulsbosch ◽  
E. Raimond
Keyword(s):  
Surface Density ◽  
Velocity Dispersion ◽  
Neutral Hydrogen ◽  
Hydrogen Gas ◽  
High Latitudes ◽  
Low Velocity

Earlier investigations have shown that there is a preponderance of negative velocities in the hydrogen gas at high latitudes, and that in certain areas very little low-velocity gas occurs. In the region 100° <l< 250°, + 40° <b< + 85°, there appears to be a disturbance, with velocities between - 30 and - 80 km/sec. This ‘streaming’ involves about 3000 (r/100)2solar masses (rin pc). In the same region there is a low surface density at low velocities (|V| < 30 km/sec). About 40% of the gas in the disturbance is in the form of separate concentrations superimposed on a relatively smooth background. The number of these concentrations as a function of velocity remains constant from - 30 to - 60 km/sec but drops rapidly at higher negative velocities. The velocity dispersion in the concentrations varies little about 6·2 km/sec. Concentrations at positive velocities are much less abundant.

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