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ISSN Online: 2377-424X

International Heat Transfer Conference 4
August 31 - September 5, 1970, Paris-Versailles, France

FLUID THERMAL DIFFUSIVITY DETERMINATION BY A PULSE TRANSIENT TEMPERATURE TECHNIQUE

Get access (open in a dialog) DOI: 10.1615/IHTC4.3260
pages 1-11

Resumo

A new transient method has been developed for the measurement of fluid thermal diffusivity in which: the fluid boundaries do not affect the measurement, bulk fluid temperature is not altered, discrimination between conduction and radiation is achieved, and only 1 cc of liquid is used. The system employs a pulsed laser coupled to a microscope to deposit energy in a local region (~ 40 μm). Microthermocouples (MTC) with junctions of 6-10 μm are used to detect the thermal transient. The MTC signal is amplified and digitally stored; repetitive analyses enable signal averaging for greater accuracy. Diffusivity determinations at 20 DC, utilizing comparative measurements with ethylene glycol as the reference fluid, give the following results: Water = 14.3, Ethyl alcohol = 8.5, l-propanol = 8.0 and l-pentanol = 7.5 (all results × 10−7 square meters/sec).