scholarly journals Three phase heat and mass transfer model for unsaturated soil freezing process: Part 1 - model development

Open Physics ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 75-83 ◽  
Author(s):  
Fei Xu ◽  
Yaning Zhang ◽  
Guangri Jin ◽  
Bingxi Li ◽  
Yong-Song Kim ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Water Content ◽  
Heat And Mass Transfer ◽  
Unsaturated Soil ◽  
Liquid Water ◽  
Soil Freezing ◽  
Freezing Process ◽  
Moisture Migration ◽  
Water Fraction ◽  
Three Phase

Abstract A three-phase model capable of predicting the heat transfer and moisture migration for soil freezing process was developed based on the Shen-Chen model and the mechanisms of heat and mass transfer in unsaturated soil freezing. The pre-melted film was taken into consideration, and the relationship between film thickness and soil temperature was used to calculate the liquid water fraction in both frozen zone and freezing fringe. The force that causes the moisture migration was calculated by the sum of several interactive forces and the suction in the pre-melted film was regarded as an interactive force between ice and water. Two kinds of resistance were regarded as a kind of body force related to the water films between the ice grains and soil grains, and a block force instead of gravity was introduced to keep balance with gravity before soil freezing. Lattice Boltzmann method was used in the simulation, and the input variables for the simulation included the size of computational domain, obstacle fraction, liquid water fraction, air fraction and soil porosity. The model is capable of predicting the water content distribution along soil depth and variations in water content and temperature during soil freezing process.

scholarly journals Three phase heat and mass transfer model for unsaturated soil freezing process: Part 2 - model validation

Open Physics ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 84-92 ◽  
Author(s):  
Yaning Zhang ◽  
Fei Xu ◽  
Bingxi Li ◽  
Yong-Song Kim ◽  
Wenke Zhao ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Unsaturated Soil ◽  
Correlation Coefficients ◽  
Soil Freezing ◽  
Freezing Process ◽  
Transfer Model ◽  
Mass Transfer Model ◽  
Three Phase ◽  
Water Contents

AbstractThis study aims to validate the three-phase heat and mass transfer model developed in the first part (Three phase heat and mass transfer model for unsaturated soil freezing process: Part 1 - model development). Experimental results from studies and experiments were used for the validation. The results showed that the correlation coefficients for the simulated and experimental water contents at different soil depths were between 0.83 and 0.92. The correlation coefficients for the simulated and experimental liquid water contents at different soil temperatures were between 0.95 and 0.99. With these high accuracies, the developed model can be well used to predict the water contents at different soil depths and temperatures.

scholarly journals New Hailstone Physics. Part I: Heat and Mass Transfer (HMT) and Growth

2014 ◽  
Vol 71 (4) ◽  
pp. 1508-1520 ◽  
Author(s):  
Roland List
Keyword(s):  
Mass Transfer ◽  
Water Content ◽  
Heat And Mass Transfer ◽  
Liquid Water ◽  
Collection Efficiency ◽  
Free Fall ◽  
Liquid Water Content ◽  
Homogeneous Surface ◽  
Surface Temperatures ◽  
Ice Fraction

Abstract An all-encompassing new theory of heat and mass transfer (HMT) and growth equations have been developed for freely falling spherical hailstones with diameters of 0.5–8 cm. The initial six variables are diameter, liquid water content, air and hailstone surface temperatures, net collection efficiency, and ice fraction of spongy deposit. They are replaced by three or four new ones, depending on the three growth categories. Two new variables are products of “old” ones: (i) the square root of the Reynolds number Re and the liquid water content and (ii) net collection efficiency and ice fraction of the spongy deposit. Only the products matter, not the individual parts. [The two variables in (ii) are as important as the two in (i).] Two old variables remain: air and surface temperatures. The HMT can be further compacted for hailstorms with specified pressure–air temperature–height profiles. Further, Re for free-fall reveals unexpected complexities—issues important to solve HMT problems. The “new hailstone physics” is based on 55 years of in-house studies of all aspects of hailstone growth, followed by 5 years of shaping these puzzle pieces and assembling them into a coherent picture. This was only possible by recognizing the free-fall mode: a special gyration that allows hailstones to grow with a radial symmetry and, thus, homogeneous surface temperature. Part II will display the surprising solutions to growth and HMT and firmly link the hailstones to mostly spongy growth with shedding that favors a hail-coupled rain mechanism.

An engineering model for coupled heat and mass transfer analysis in heated concrete

2002 ◽  
Vol 216 (2) ◽  
pp. 213-222 ◽  
Author(s):  
L y Li ◽  
J A Purkiss ◽  
R T Tenchev
Keyword(s):  
Mass Transfer ◽  
Mass Transport ◽  
Heat And Mass Transfer ◽  
Liquid Water ◽  
Gaseous Mixture ◽  
Sorption Isotherms ◽  
Engineering Model ◽  
Water Saturated ◽  
Mass Transport Equation ◽  
Heated Concrete

In this paper an engineering model for coupled heat and mass transfer in heated concrete is proposed. The model considers the heat transfer and mass transport of liquid water and gaseous mixture. The evaporation of liquid water is assumed to be related to the imbalance pressure between liquid water and water vapour controlled by the ideal gaseous mixture pressure and water saturated pressure. Thus, the content of liquid water is determined directly from its mass transport equation rather than through assumed sorption isotherms as in most existing models. Numerical results for temperature, pore pressure and contents of liquid water and gaseous mixture are presented. Some important features are highlighted through the discussion of results.

Physical statement of the problem for a numerical model of soil freezing and heaving taking into account heat and mass transfer

2021 ◽  
pp. 244-256
Author(s):  
Виктор Григорьевич Чеверев ◽  
Евгений Викторович Сафронов ◽  
Алексей Александрович Коротков ◽  
Александр Сергеевич Чернятин
Keyword(s):  
Finite Element Method ◽  
Mass Transfer ◽  
Finite Element ◽  
Numerical Model ◽  
Boundary Conditions ◽  
Heat And Mass Transfer ◽  
Soil Freezing ◽  
The Finite Element Method ◽  
Freezing Front ◽  
Element Method

Существуют два основных подхода решения задачи тепломассопереноса при численном моделировании промерзания грунтов: 1) решение методом конечных разностей с учетом граничных условий (границей, например, является фронт промерзания); 2) решение методом конечных элементов без учета границ модели. Оба подхода имеют существенные недостатки, что оставляет проблему решения задачи для численной модели промерзания грунтов острой и актуальной. В данной работе представлена физическая постановка промерзания, которая позволяет создать численную модель, базирующуюся на решении методом конечных элементов, но при этом отражающую ход фронта промерзания - то есть модель, в которой объединены оба подхода к решению задачи промерзания грунтов. Для подтверждения корректности модели был проделан ряд экспериментов по физическому моделированию промерзания модельного грунта и выполнен сравнительный анализ полученных экспериментальных данных и результатов расчетов на базе представленной численной модели с такими же граничными условиями, как в экспериментах. There are two basic approaches to solving the problem of heat and mass transfer in the numerical modeling of soil freezing: 1) using the finite difference method taking into account boundary conditions (the boundary, for example, is the freezing front); 2) using the finite element method without consideration of model boundaries. Both approaches have significant drawbacks, which leaves the issue of solving the problem for the numerical model of soil freezing acute and up-to-date. This article provides the physical setting of freezing that allows us to create a numerical model based on the solution by the finite element method, but at the same time reflecting the route of the freezing front, i.e. the model that combines both approaches to solving the problem of soil freezing. In order to confirm the correctness of the model, a number of experiments on physical modeling of model soil freezing have been performed, and a comparative analysis of the experimental data obtained and the calculation results based on the provided numerical model with the same boundary conditions as in the experiments was performed.

A three-phase solid-liquid-gas slug flow mechanistic model coupling hydrate dispersion formation with heat and mass transfer

2018 ◽  
Vol 178 ◽  
pp. 222-237 ◽  
Author(s):  
Carlos L. Bassani ◽  
Fausto A.A. Barbuto ◽  
Amadeu K. Sum ◽  
Rigoberto E.M. Morales
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Slug Flow ◽  
Mechanistic Model ◽  
Model Coupling ◽  
Three Phase ◽  
Solid Liquid
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