Flame Stabilization Through Forcing: Velocity Measurements
作者:
JUN LI,
SUMANTA ACHARYA,
期刊:
Combustion Science and Technology
(Taylor Available online 2000)
卷期:
Volume 152,
issue 1
页码: 1-21
ISSN:0010-2202
年代: 2000
DOI:10.1080/00102200008952124
出版商: Taylor & Francis Group
数据来源: Taylor
摘要:
The differences in the flow field of an unforced unstable flame and a forced stable flame was examined through velocity and temperature measurements. Measurements were made in open atmosphere with an air-assist atomizing nozzle consisting of a central liquid-fuel (ethanol) stream, and a swirling primary air stream. Measurements made include the temperature, and CH/C2emission spectra for the forced stable flame, and cold-flow velocity measurements for both the air stream and the fuel droplets with and without primary-air forcing. The temperature distributions indicate that the stable flame is characterized by three distinct zones in the axial direction: (1) a low-temperature droplet heat-up and vaporization zone near the base of the flame, (2) an intermediate zone with three regions in the radial direction: a low-temperature droplet vaporization region straddled by two high-temperature combustion regions, one in the center and the other along the outer edges respectively, and (3) an upper high-temperature zone with combustion across the entire cross-section. The intermediate zone is most effected by forcing with substantial increases in the velocities, entrainment or volume flow rate, and turbulence levels. These increases contribute to improved vaporization and fuel-air mixing and therefore higher temperatures near the base of the flame. The forcing-induced improved mixing and the higher temperatures near the base of the flame are responsible for the flame stabilization.
点击下载:
PDF (6818KB)
返 回