Determination of gaseous heat transfer coefficients at elevated temperatures

An experimental method of measuring gaseous heat transfer coefficients of two noble gases, as well as several binary mixtures of these gases, is described in this paper. The method employed during this study involved measuring the cooling rate of a “hot wire” that was surrounded by a nearly static atmosphere of either pure Helium, pure Argon, or a binary mixture of these gases. Initial wire temperature increases, in the presence of each gas or gas mixture tested, were created by a controlled electrical heating process just prior to the onset of the cooling process. The findings obtained during this study are believed to be of importance in providing a better quantitative understanding of the importance of using very low molecular weight gases during the cooling process that accompanies the drawing of optical fibers from heated glass preforms.