Experimental Study on Flow and Heat Transfer in a 19.6-m Microtube

Author: Zhigang L.  

Publisher: Taylor & Francis Ltd

ISSN: 1521-0480

Source: Experimental Heat Transfer, Vol.22, Iss.3, 2009-07, pp. : 178-197

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Abstract

The flow and the heat transfer characteristics in a quartz microtube with an inner diameter of 0.0196 mm are investigated experimentally. Measuring the pressure drop between the inlet and outlet of the microtube and the average temperature of the microtube wall heated by steam when the working fluid is distilled water, the corresponding friction factors and Nusselt number are obtained. The experimental results show the friction factors in the microtube exceed those of the Hagen-Poiseuille prediction due to the predominance of the effects of the electrical double layer and the entrance. Also, the experimental Nusselt number is less than the classical laminar at Reynolds number < 500="" due="" to="" the="" effect="" of="" the="" variation="" of="" the="" thermophysical="" properties="" with="" the="" temperature.="">