Fluid radiation effects in the transient hot-wire technique
- 51 Downloads
The transient hot-wire technique is widely used for absolute measurements of the thermal conductivity of fluids. Refinement of this method has resulted in a capability for accurate and simultaneous measurement of both thermal conductivity and thermal diffusivity together with a determination of the specific heat. However, these measurements, especially those for the thermal diffusivity, may be significantly influenced by fluid radiation.
The present work investigates the effect of fluid radiation on the measurements of the thermal conductivity of propane. Recently developed corrections have been used to examine this assumption and rectify the influence of even weak fluid radiation. Measurements at 372 K with a hot-wire instrument demonstrate the presence of radiation effects in both the liquid and vapor phase. The influence is much more pronounced in liquid propane at 15.5 MPa than in the vapor phase at 881.5 kPa. The technique employed to obtain radiation-free thermal conductivity measurements is described.
Keywordsargon natural convection n-pentane propane thermal conductivity thermal diffusivity thermal radiation transient hot wire technique
Unable to display preview. Download preview PDF.
- 3.X. Qiu, N. Mathis and K. Schimdt, Thermochim. Acta, in press.Google Scholar
- 8.J. J. Healy, J. J. De Groot and J. Kestin, Physica, 82C (1976) 392.Google Scholar
- 9.L. Sun, Simultaneous Measurement of Thermal Conductivity and Thermal Diffusivity, PhD Thesis, University of New Brunswick, Fredericton, NB, Canada (2001).Google Scholar
- 10.Y. Shi, Radiation Effects in Transient Hot-Wire Technique: Simultaneous Measurement of Thermal Conductivity and Diffusivity of Propane, MScE Thesis, University of New Brunswick, Saint John, NB, Canada (2006).Google Scholar
- 11.E. W. Lemmon, A. P. Peskin, M. O. Melinden and D. G. Friend, NIST Standard Reference Data Base 12, Version 5. The U.S. Secretary of Commence on Behalf of the United States of America.Google Scholar