Theoretical and Numerical Analyses on Hydro–Thermal–Salt–Mechanical Interaction of Unsaturated Salinized Soil Subjected to Typical Unidirectional Freezing Process

Experimental studies were conducted on unidirectional and multidirectional freezing of artificial soils in a rectangular cavity. The ice lenses were observed through transparent plexiglass plate. Temperature gradients in soil specimen were obtained during freezing process. The experimental results indicated that the temperature gradient may change the shape of ice lenses. The amount of frost heave of multidirectional freezing was less than unidirectional freezing, so multidirectional freezing mode is helpful to restrain vertical frost heave.

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A Study on the Coupled Model of Hydrothermal-Salt for Saturated Freezing Salinized Soil

Mathematical Problems in Engineering ◽

10.1155/2017/4918461 ◽

2017 ◽

Vol 2017 ◽

pp. 1-12 ◽

Cited By ~ 5

Author(s):

Xudong Zhang ◽

Qing Wang ◽

Gang Wang ◽

Wenhua Wang ◽

Huie Chen ◽

...

Keyword(s):

Soil Column ◽

Salt Content ◽

Coupled Model ◽

Salt Transport ◽

Freezing Process ◽

Unfrozen Water ◽

Moisture Migration ◽

Conservation Of Energy ◽

Simulation And Experiment ◽

Salinized Soil

Water and heat interact in the process of freezing for the saturated soil. And for the salinized soil, water, heat, and salt interact in the freezing process, because salinized soil has soluble salt. In this paper, a one-dimensional mathematical coupled model of hydraulic-thermal-salt is established. In the model, Darcy’s law, law of conservation of energy, and law of conservation of mass are applied to derive the equations. Consider that a saturated salinized soil column is subjected to the condition of freezing to model the moisture migration and salt transport. Both experiment and numerical simulation under the same condition are developed in the soil column. Then the moisture content and salt content between simulation and experiment are compared. The result indicates that simulation matches well with the experiment data, and after 96 hours, the temperature distribution becomes stable, freezing front reaches a stable position, and a lot of unfrozen water has time to migrate. Besides, the excess salt precipitates when the concentration is greater than the solubility, and the precipitation is distributed discontinuously. These results can provide reference for engineering geology and environmental engineering in cold region and saline soil area.

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Experimental Verification of Expedited Freezing of Nanoparticle-Enhanced Phase Change Materials (NEPCM)

ASME/JSME 2011 8th Thermal Engineering Joint Conference ◽

10.1115/ajtec2011-44165 ◽

2011 ◽

Cited By ~ 7

Author(s):

Liwu Fan ◽

J. M. Khodadadi

Keyword(s):

Thermal Conductivity ◽

Phase Change ◽

Phase Change Materials ◽

Freezing Process ◽

Freezing Front ◽

One Dimensional ◽

Unidirectional Freezing ◽

Finite Slab ◽

The One ◽

Pure Cyclohexane

Highly-conductive nano-sized particles are dispersed into phase change materials (PCM) to improve their effective thermal conductivity, thus leading to suspensions that are referred to as nanoparticle-enhanced PCM (NEPCM). In order to assess the extent of expedited phase change due to the enhanced thermal conductivity, the one-dimensional unidirectional freezing process of NEPCM in a finite slab was investigated experimentally. Thermocouple readings were recorded at several equally-spaced locations along the freezing direction in order to monitor the progress of the freezing front. As an example, cyclohexane (C6H12) and copper oxide (CuO) nanoparticles were chosen to develop the NEPCM with three different volume fractions (0.5, 1.0, and 2.0 vol%). It was shown that the freezing rate for the 0.5 vol% NEPCM is considerably raised as compared to pure cyclohexane. However, further increase of the fraction of nanoparticles to 1.0 and 2.0 vol% did not linearly expedite freezing. Significant sedimentation of nanoparticles was observed for the 2.0 vol% NEPCM. Additionally, in this case the undesirable supercooling phenomenon was enhanced, which suppresses the growth rate of the solidified NEPCM.

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