Diffusion flame

About: Diffusion flame is a research topic. Over the lifetime, 9266 publications have been published within this topic receiving 233522 citations.

Some problems of flame spread along a liquid surface

Abstract: Recent studies of flame spread along a liquid surface were surveyed. It is clear that theflame spread in the temperature region below the flash point of fuel is mainly controlled through the liquid flow caused by surface tension and buoyancy force, as suggested by Roberts, Glassman, and others. However, since a region where no surface flow is observed and a particular behavior of pulsating flame spread are also found for alcohol fuels, the phenomena in question do not seem to be as simple as previously thought. In this paper, flame spread is classified into three groups of uniform, pulsating, and pseudo-uniform spread, depending on the temperature of the liquid, and the mechanism of flame spread in each region is discussed in the light of new experimental results.

Laser-induced incandescence applied to droplet combustion

Abstract: Laser-induced incandescence (LII) is ideally suited for obtaining high temporally and spatially resolved measurements of soot volume fraction in transient combustion phenomena. We demonstrate qualitative two-dimensional nonintrusive optical measurements of the soot evolution versus time from single fiber-supported burning fuel droplets of heptane and decane. Quantitative measurement of the soot volume fraction is also demonstrated through calibration of the LII signal against a small coflow ethylene diffusion flame.

Asymptotic Theory of Diffusion-Flame Extinction with Radiant Loss from the Flame Zone

Abstract: Laminar diffusion flames in counterfiow configurations such as stagnation-point boundary layers are analyzed by methods of matched asymptotic expansions with large parameters being the temperature sensitivities of the rates of chemical heat generation and radiant heat loss. Formulas are derived defining critical conditions for flame extinction, including influences of radiant loss.

Studies on the structure of a spray combustion flame

Abstract: To clarify the flame structure of a spray burner, the following experiments and analysis were carried out. (1) Droplet and temperature distributions, flow velocity, and gas composition were measured in the flame of an air-atomizing burner. It was found that the region where the droplets exist is limited to a small area above the burner nozzle. From the correlation between the above various distributions, it was concluded that most of the droplets in the flame do not burn individually, but that fuel vapor from the droplets concentrates and burns like a gas diffusion flame. (2) Various measurements were then made on a spray combustion flame and a turbulent gas diffusion flame under the same conditions. Comparing the two sets of data, it was found that the flames are similar in structure. (3) Assuming that the droplets evaporate in the flame, their behavior was analyzed by making use of the knowledge which has been obtained for a single droplet. The calculated results were in fairly close agreement with the experimental results. The above facts suggest the possibility that the spray combustion flame could be treated theoretically by applying the information for a single droplet and for a turbulent gas diffusion flame.