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Temperature Measurement by Holographic Interferometry in Liquids.


pdf icon Temperature Measurement by Holographic Interferometry in Liquids. (868 K)
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

Keywords:

pool fires; temperature measurements; interferometry; holographic interferometry

Abstract:

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.