Measurement of Transient 2-D Profiles of Velocity and Fuel-Concentration Over Liquids.
Measurement of Transient 2-D Profiles of Velocity and
Fuel-Concentration Over Liquids.
Ito, A.; Narumi, A.; Konishi, T.; Tashtoush, G.; Saito,
K.; Cremers, C. J.
NIST GCR 96-704; 24 p. December 1996.
Sponsor:National Institute of Standards and Technology,
Available from: National Technical Information Service
Order number: PB97-137574
pool fires; velocity; temperature; flame spread
We recently developed two different optical techniques
in order to simultaneously measure transiet 2-D profiles
of velocity, temperature and fuel concentration which
were generated by a spreading flame over liquids. The
first technique, PTLS employs a particle-track system
combined with a laser-sheet system and a high speed
camera, while the second technique employs a dual
wavelength holographic interferometer (DWHI). The PTLS
system revealed transient 2 D profiles of flame incuded
flow, while DWHI revealed 2 D profiles of fuel
concentration over liquids. In this paper we present a
series of velocity profiles for a pulsating flame spread
over propanol and concentration profiles for gaseous
propanol determined with PTLS and DWHI respectively.
Other researchers have predicted the formation of small
twin circulations, one a gas-phase circulation just
ahead of the flame's leading edge, and the other a small
liquid circulation just underneath the gas-phase
circulation. Our PTLS results confired these
predictions, i.e., the formation of a
millimeter-diameter circulation in the gas phase and an
accompanying liquid flow. Based on these data, we offer
a phenomenological explanation of the mechanism of
pulsating flame spread. In addition, we show that DWHI
is a very promising technique for measuring transient
fuel-concentration profiles over liquids.