HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Hadas, A. Search for Related Content PubMed Articles by Hadas, A. Agricola Articles by Hadas, A.

A Comparison between Two Methods of Determining the Thermal Diffusivity of a Moist Soil¹

ABSTRACT

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.

¹ Contribution from the Volcani Institute for Agricultural Research, Division of Soil Technology, Rehovot, Israel.

² Soil Physicist, The Volcani Inst. for Agr. Res., Div. of Soil Technology, Rehovot, Israel. At present with the Dep. of Soils & Meteorology, Utah State Univ., Logan, Utah.

Received for publication June 21, 1967. Accepted for publication October 11, 1967.