Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7055863 | International Journal of Heat and Mass Transfer | 2016 | 10 Pages |
Abstract
The conventional transient plane source (TPS) method cannot accurately measure bulk thermal conductivity of thin films and coatings, because of the inclusion of thermal contact resistances in the results. In this study, a new modified TPS method is proposed that allows accurate measurement of bulk thermal conductivity of thin films and coatings. For this purpose, first, a hot disk testbed is used to measure the total thermal resistance for different thicknesses of a sample in the TPS test column. The bulk thermal conductivity is then deconvoluted from the results. Experiments have been performed on ethylene tetrafluoroethylene (ETFE) sheets, Nafion membranes, and gas diffusion layers (GDLs) with different thicknesses using the proposed method, and the results have been cross-checked with the data obtained from the guarded hot plate method, as per ASTM standard C177-13. The present modified TPS method yields thermal conductivity values of 0.174 ± 0.002 W·mâ1·Kâ1 for ETFE and 0.243 ± 0.007 W·mâ1·Kâ1 for Nafion, while the values measured by the guarded hot plate method are 0.177 ± 0.002 W·mâ1·Kâ1 for ETFE and 0.214 ± 0.003 W·mâ1·Kâ1 for Nafion. The GDL results, on the other hand, change with mechanical pressure, and about 15.7% difference is observed between the GDL results of the two methods. Overall, the developed method is proved to be highly reliable, quick, and accurate.
Keywords
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Fluid Flow and Transfer Processes
Authors
Mohammad Ahadi, Mehdi Andisheh-Tadbir, Mickey Tam, Majid Bahrami,