A vertical combustion wind tunnel was built in which confined turbulent diffusion flames were studied. Measurements were made of the mean soot volume fraction in turbulent ethylene flames using laser extinction. Velocities were measured with laser Doppler velocity, and radiation was detected with a wide-view-angle radiometer. The flames were burned under three conditions of axial pressure gradient: 0, -32, and -92 Pa/m. The accelerating flow was produced by a converging wind-tunnel working section. It was found that the latter pressure gradient caused the soot loading to fall by one-half, with a commensurate fall in the radiation emitted by the flame. The flame was shorter when it was accelerated. Turbulence intensities were also greater in the convergent duct. The results indicate the potential impact of pressure gradients on the relatively slow chemistry of soot formation.
|Original language||English (US)|
|Number of pages||4|
|State||Published - Jun 1991|
ASJC Scopus subject areas
- Aerospace Engineering