A Comparison between Two Methods of Determining the Thermal Diffusivity of a Moist Soil1
- A. Hadas2
Two types of solutions of the heat flow equation were discussed and proposed recently as methods for evaluating the thermal diffusivity of soils. The first one is the harmonic solution for a sine heat wave while the second uses the Laplace transform for solving the heat flow equation. This work was carried out in order to compare the thermal diffusivity values obtained by using these two solutions. Experimental data were analyzed for dry soil as well as for wet soil having 4.5, 7.8, and 14.5% water on dry weight basis.
The thermal treatments were: three types of heat waves, a sine wave, half square and a full square wave, all having an amplitude of 6C and periods of 8 and 16 min.
For dry soil the sine wave solution yielded lower values than the Laplace solution did. For the wet soil the same trend was observed for the short period while for the longer period a cross-over, namely, higher values were obtained using the sine wave solution than those obtained by the Laplace solution.
These differences are discussed in the light of the experimental conditions and moisture transfer during the heating period.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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