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Transfer of Heat by Conduction and Vapor Movement in a Closed Soil System
Author(s) -
Westcot D. W.,
Wierenga P. J.
Publication year - 1974
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1974.03615995003800010012x
Subject(s) - heat flux , water vapor , thermal conduction , flux (metallurgy) , heat transfer , thermodynamics , diffusion , chemistry , materials science , physics , organic chemistry
A study was made to determine the importance of vapor flow to the heat transfer process in soil. Soil temperature and water content were measured in sealed columns, 7.6 cm in diameter and 32 cm in length. The columns were inserted into a field plot and exposed to daily temperature fluctuations for periods varying from 1 to 6 days. A computer simulation model was developed to predict vapor movement and the transfer of heat by conduction and by vapor diffusion. Agreement was found between observed and computed water and temperature distributions in the columns. Comparison of observed and computed temperature profiles shows that for an accurate prediction of the soil temperature in the upper soil profile, heat transfer by vapor movement must be taken into account. Vapor flux accounted for 40–60% of the heat flux in the surface 0–2 cm of the soil profile during periods of the day. Vapor flux past the 11‐cm depth, depending on the time of the day, accounted for 17–34% of the total heat flux. Vapor flux still accounted for 20–25% of the total heat flux at the 25‐cm depth although the total heat flux density was no more than 10% of its surface value.