Coupled Liquid Water, Water Vapor, and Heat Transport Simulations in an Unsaturated Zone of a Sandy Loam Field

Soil Science ◽  
2011 ◽  
Vol 176 (8) ◽  
pp. 387-398 ◽  
Author(s):  
Sanjit K. Deb ◽  
Manoj K. Shukla ◽  
Parmodh Sharma ◽  
John G. Mexal
Keyword(s):  
Water Vapor ◽  
Heat Transport ◽  
Liquid Water ◽  
Unsaturated Zone ◽  
Sandy Loam

scholarly journals Determination of State Variables in Textile Composite with Membrane During Complex Heat and Moisture Transport

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Ryszard Korycki
Keyword(s):  
Water Vapor ◽  
Mass Transport ◽  
Transport Equation ◽  
Heat Transport ◽  
Liquid Water ◽  
Initial Conditions ◽  
State Variables ◽  
Coupled Transport ◽  
Material Transport ◽  
Mass Transport Equation

AbstractThe cotton-based composite is equipped with a single/double semipermeable membrane made of polyurethane (PU) (100%), which blocks liquid transport to the surrounding environment. The complex problem analyzed involves the coupled transport of water vapor within the textile material, transport of liquid water in capillaries, as well as heat transport with vapor and liquid water. The problem can be described using the mass transport equation for water vapor, heat transport equation, and mass transport equation for liquid moisture, accompanied by the set of corresponding boundary and initial conditions. State variables are determined using a complex multistage solution procedure within the selected points for each layer. The distributions of state variables are determined for different configurations of membranes.

Components of apparent soil thermal conductivity measured by the heat pulse method

2021 ◽  
Author(s):  
Sen Lu
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Water Vapor ◽  
Water Content ◽  
Liquid Water ◽  
Sandy Loam ◽  
Sensible Heat ◽  
Soil Thermal Conductivity ◽  
Vapor Diffusion ◽  
Vapor Transfer

<p>Knowledge on the components of apparent soil thermal conductivity (λ) across various water contents (θ) and temperatures is important to accurately understand soil heat transfer mechanisms. In this study, soil thermal conductivity was measured for sandy loam and silty clay soils at various temperatures and air pressures using a transient method. Four components of λ, namely, heat conduction, latent heat transfer by water vapor diffusion, sensible heat transfer by liquid water, and sensible heat transfer by water vapor diffusion were quantified. Results showed that in uniform soils, the magnitudes of sensible heat transfers by liquid water and water vapor were negligible during these transient measurements. The contribution of latent heat transfer through vapor diffusion to total heat transfer increased as temperature increased, and the peak value occurred at an intermediate water content. The water content at which the maximum vapor diffusion occurred varied with soil texture. In addition to the four calculated components, a significant residual contribution to λ caused by an unidentified vapor transfer mechanism was observed between 3.5°C and 81°C. For example, calculations indicated that approximately 66% of the sandy loam λ at θ=0.11 m<sup>3</sup> m<sup>−3</sup> was caused by an unidentified vapor transfer mechanism at 81°C. This extra contribution by vapor transfer could be explained either as enhanced vapor diffusion or by an advection mechanism. Further investigation is needed to clarify whether enhanced diffusion or advection is occurring in unsaturated soils. </p>

New Method for Estimation of Contaminant Travel Rate in Unsaturated Zone under Irrigated Soils

1993 ◽  
Vol 27 (7-8) ◽  
pp. 173-178 ◽  
Author(s):  
M. Zilberbrand
Keyword(s):  
Water Content ◽  
Unsaturated Zone ◽  
Sandy Loam ◽  
Chestnut Soil ◽  
Deep Penetration ◽  
Groundwater Recharge Rate ◽  
Capillary Tension ◽  
Travel Rate ◽  
Tracer Experiments ◽  
Irrigated Soils

In a thick unsaturated zone, when quick deep penetration of rain and irrigation water is absent, at the depths below 3-5 m there exists a zone of downwards quasi-steady water flow. Darcy's water velocity in this zone remains constant with depth and equal to the groundwater recharge rate; unit hydraulic head gradient occurs above the capillary fringe. Therefore, contaminant travel rate is equal to the ratio of hydraulic conductivity (K) and effective volumetric water content (θef). Field tracer experiments and laboratory K and θef determinations were carried out for several representative irrigated lots in the South Ukraine. The dependence of θef on capillary tension was studied for the first time. For loess loam with a capillary tension decreasing from 46 kPa to 0, θef nonlinearly increases from 12% to 27-28%. The effective water content portion (β1) of the total water content increases nonlinearly from 0.38 to 0.65-0.7. The β1 values were estimated for different unsaturated sedimentary rocks. For a capillary tension of about 5 kPa β1 values were: 0.88-0.99 for sands, about 0.65 for loess loam and chestnut soil, about 0.6 for sandy loam, about 0.32 for limestone and about 0.07 for clay. Calculated chloride travel rates in loess loams under irrigated soils fit the values of 0.001-0.003 m/day, determined by the results of field tracer experiments.

scholarly journals Numerical Investigation of the Deformable Porous Media Treated by the Intermittent Microwave

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 757
Author(s):  
Tianyi Su ◽  
Wenqing Zhang ◽  
Zhijun Zhang ◽  
Xiaowei Wang ◽  
Shiwei Zhang
Keyword(s):  
Porous Media ◽  
Heat Transport ◽  
Liquid Water ◽  
Von Mises Stress ◽  
Temperature Deformation ◽  
Local Maxima ◽  
Whole Process ◽  
Surface Areas ◽  
Pulse Ratio ◽  
Von Mises

A 2D axi-symmetric theoretical model of dielectric porous media in intermittent microwave (IMW) thermal process was developed, and the electromagnetic energy, multiphase transport, phase change, large deformation, and glass transition were taken into consideration. From the simulation results, the mass was mainly carried by the liquid water, and the heat was mainly carried by liquid water and solid. The diffusion was the dominant mechanism of the mass transport during the whole process, whereas for the heat transport, the convection dominated the heat transport near the surface areas during the heating stage. The von Mises stress reached local maxima at different locations at different stages, and all were lower than the fracture stress. A material treated by a longer intermittent cycle length with the same pulse ratio (PR) tended to trigger the phenomena of overheat and fracture due to the more intense fluctuation of moisture content, temperature, deformation, and von Mises stress. The model can be extended to simulate the intermittent radio frequency (IRF) process on the basis of which one can select a suitable energy source for a specific process.

scholarly journals Selecting Characteristic Raman Wavelengths to Distinguish Liquid Water, Water Vapor, and Ice Water

2010 ◽  
Vol 14 (3) ◽  
pp. 209-214 ◽  
Author(s):  
Sun-Ho Park ◽  
Yong-Gi Kim ◽  
Duk-Hyeon Kim ◽  
Hai-Du Cheong ◽  
Won-Seok Choi ◽  
...  
Keyword(s):  
Water Vapor ◽  
Liquid Water ◽  
Ice Water

scholarly journals Drying parameters of rendering mortars

2018 ◽  
Vol 18 (2) ◽  
pp. 7-19 ◽  
Author(s):  
Maria Cláudia de Freitas Salomão ◽  
Elton Bauer ◽  
Claudio de Souza Kazmierczak
Keyword(s):  
Water Vapor ◽  
Water Transport ◽  
Liquid Water ◽  
Water Vapor Permeability ◽  
Water Vapor Transport ◽  
Experimental Program ◽  
Vapor Permeability ◽  
Capillary Absorption ◽  
Drying Behavior ◽  
Drying Curves

Abstract The objective of this article was to study the drying behavior of rendering mortars. Cement-lime mortars with different mix proportions were evaluatedto analyze the influence of mix materials on water transport. The experimental program was produced to observe the transport of liquid water and vapor water in mortars during the drying process. The liquid water transport was studied through capillary absorption and the water vapor transport by the water vapor permeability test. The drying curves used to investigate drying kinetics were obtained according to the methodology recommended by European standard EN 16322. In summary, it is possible to affirm that the aggregate, the binder and water contents determine the behavior of the mortars regarding water transport. The drying index is considered a good indicator of the easiness of both liquid and vapor water transport.

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