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

This Article Figures Only Full Text 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 Google Scholar Articles by Lu, X. Articles by Gong, Y. PubMed Articles by Lu, X. Articles by Gong, Y. Agricola Articles by Lu, X. Articles by Gong, Y. Related Collections Flow Soil Physics

SOIL PHYSICS

Experimental Investigation of Thermal Dispersion in Saturated Soils with One-Dimensional Water Flow

College of Resource and Environmental Sciences, China Agricultural Univ. Beijing, China 100193

^* Corresponding author (gongys{at}cau.edu.cn).

Microscopic differences in soil pore water velocity cause hydrodynamic dispersion of solute transport. By analogy, thermal dispersion should be considered in soils where water and heat flow occur simultaneously. Few published data are available regarding thermal dispersion in soils. In this study, we investigated thermal dispersion influences on heat transport in saturated soils with one-dimensional water flow. A new soil container was developed to eliminate wall flow influences on saturated water flow. An inverse model was applied to obtain the thermal dispersion coefficient (_d) by fitting the conduction–convection–dispersion (CCD) model to soil temperature change as a function of time from heat-pulse measurements. Thermal dispersion became significant when the water flux was higher than a threshold value. In the studied water flux range, the maximum contribution of hydrodynamic dispersion to effective heat conduction [_d/(_d + ₀), where ₀ is the bulk thermal conductivity] was 6, 9, and 12% in a sand, a silt loam, and a sandy clay loam, respectively. A power function relationship was established between _d and the soil water flux density (J_w): _d = kJ_w^0.9, where k is a coefficient related to soil texture. Experimental evaluation indicated that, compared with the conduction–convection model, the CCD model performed better in describing the temperature change vs. time data from heat-pulse measurements.

Abbreviations: CCD, conduction–convection–dispersion