Temperature Measurement by Holographic Interferometry in Liquids.
Temperature Measurement by Holographic Interferometry in
Ito, A.; Narumi, A.; Saito, K.; Cremers, C. J.
NIST GCR 96-704; 10 p. December 1996.
Transport Phenomena in Combustion. Proceedings of the
8th International Symposium on Transport Phenomena in
Combustion (ISTP-VIII). Volume 2. July 16-20, 1995,
San Francisco, CA, Taylor and Francis, Washington, DC,
Chan, S. H., Editor(s), 1657-1668 pp, 1996.
Available from: National Technical Information Service
ON BOOK SHELF: TJ254.5.I59 1995
Order number: PB97-137574
pool fires; temperature measurements; interferometry;
Detailed temperature measurements of the condensed phase
are important for the study of flame spread over liquids
and liquid-pool fires leading to boilover. The
measurement requires high spatial resolution near the
interface between liquid and gas, where a steep
temperature gradient is formed and that controls
heat-transfer process between the two phases.
Conventional thermocouple techniques have limitations on
accurate measurements in this type of senstitive
location because the thermocapillary effect of the
thermocouple bead significantly distorts the original
temperature structure near the interface. To avoid such
interference, we developed a holographic interferometry
(HI) technique that is non-intrusive and is capable of
detecting nearly simultaneously a sudden and minute
temperature change occurring in a distributed area. The
thermo-optical coefficients of liquids are two orders of
magnitude higher than that of gases. Therefore, if an
interferogram was obtained simultaneously for the
interface region between a gas and a liquid, the gas
phase hologram is two orders of magnitude less
senstitive than the liquid phase hologram. To enhance
the sensitivity in the gas phase, a dual wave-length
holography was applied. In this study, we show that HI
is a very useful temperature measurement technique, and
the estimated errors are so small that they cause no
significant errors when the HI data are used for
quantitative analysis. This paper summarizes recent
progress made on the application of HI to highly
transient phenomena, such as the studies of flame spread
and liquid-pool fires.