Analysis of Heat and Moisture Transfer Beneath Freezer Foundations-Part II

2004 ◽  
Vol 126 (2) ◽  
pp. 726-731 ◽  
Author(s):  
Moncef Krarti ◽  
Pirawas Chuangchid ◽  
Pyeongchan Ihm
Keyword(s):  
Thermal Conductivity ◽  
Heat Conduction ◽  
Numerical Solution ◽  
Moisture Transfer ◽  
Temperature Profiles ◽  
Two Dimensional ◽  
Soil Thermal Conductivity ◽  
Heat And Moisture Transfer ◽  
Conduction Model ◽  
Heat And Moisture

This paper discusses selected results from a numerical solution of two-dimensional heat and moisture transfer within frozen and unfrozen soils beneath freezer slab foundations. In particular, the numerical solution is used to determine soil temperature profiles as well as freezer foundation heat gains. Finally, an effective soil thermal conductivity is successfully utilized in a pure heat conduction model to predict ground-coupled heat gains for freezers.

Ground-Coupled Heat and Moisture Transfer From Buildings: Part 2 — Application

2001 ◽  
Author(s):  
Michael P. Deru ◽  
Allan T. Kirkpatrick
Keyword(s):  
Heat Transfer ◽  
Moisture Transfer ◽  
Transfer Program ◽  
Soil Thermal Conductivity ◽  
Heat And Moisture Transfer ◽  
Conduction Model ◽  
Building Foundation ◽  
Dimensional Finite Element ◽  
Coupled Heat And Moisture ◽  
Heat And Moisture

Abstract In this paper the effects of moisture on the heat transfer from two basic types of building foundations, a slab-on-grade and a basement, are examined. A two-dimensional finite element heat and moisture transfer program is used to show the effects of precipitation, soil type, foundation insulation, water table depth, and freezing on the heat transfer from the building foundation. Comparisons are made with a simple heat conduction model to illustrate the dependency of the soil thermal conductivity on moisture content.

scholarly journals Ground-Coupled Heat and Moisture Transfer from Buildings Part 2–Application

2001 ◽  
Vol 124 (1) ◽  
pp. 17-21 ◽  
Author(s):  
Michael P. Deru ◽  
Allan T. Kirkpatrick
Keyword(s):  
Heat Transfer ◽  
Moisture Transfer ◽  
Transfer Program ◽  
Soil Thermal Conductivity ◽  
Heat And Moisture Transfer ◽  
Conduction Model ◽  
Building Foundation ◽  
Dimensional Finite Element ◽  
Coupled Heat And Moisture ◽  
Heat And Moisture

In this paper, the effects of moisture on the heat transfer from two basic types of building foundations, a slab-on-grade and a basement, are examined. A two-dimensional finite element heat and moisture transfer program is used to show the effects of precipitation, soil type, foundation insulation, water table depth, and freezing on the heat transfer from the building foundation. Comparisons are made with a simple heat conduction model to illustrate the dependency of the soil thermal conductivity on moisture content.

Simultaneous determination of thickness, thermal conductivity and porosity in textile material design

2016 ◽  
Vol 24 (1) ◽  
Author(s):  
Dinghua Xu ◽  
Peng Cui
Keyword(s):  
Thermal Conductivity ◽  
Human Body ◽  
Moisture Transfer ◽  
Least Squares Method ◽  
Weighted Least Squares ◽  
Optimal Solution ◽  
Comfort Level ◽  
Textile Material ◽  
Heat And Moisture Transfer ◽  
Heat And Moisture

AbstractThe thickness, thermal conductivity and porosity of textile material are three key factors which determine the heat-moisture comfort level of the human body to a large extent based on the heat and moisture transfer process in the human body-clothing-environment system. This paper puts forward an Inverse Problem of Textile Thickness-Heat conductivity-Porosity Determination (IPT(THP)D) based on the steady-state model of heat and moisture transfer and the heat-moisture comfort indexes. Adopting the idea of the weighted least-squares method, we formulate IPT(THP)D into a function minimization problem. We employ the Particle Swarm Optimization (PSO) method to stochastically search the optimal solution of the objective function. We put the optimal solution into the corresponding direct problem to verify the effectiveness of the proposed numerical algorithms and the validity of the IPT(THP)D.

scholarly journals Nonlocal Thermodynamics: Mathematical Model of Two-Dimensional Thermal Conductivity

2021 ◽  
Vol 321 ◽  
pp. 03005
Author(s):  
George Kuvyrkin ◽  
Inga Savelyeva ◽  
Daria Kuvshinnikova
Keyword(s):  
Thermal Conductivity ◽  
Mathematical Model ◽  
Heat Conduction ◽  
Numerical Solution ◽  
Complex Structure ◽  
Modern World ◽  
Nonlocal Term ◽  
Material Structure ◽  
Two Dimensional ◽  
Differential Heat

Nonlocal models of thermodynamics are becoming more and more popular in the modern world. Such models make it possible to describe materials with a complex structure and unique strength and temperature properties. Models of nonlocal thermodynamics of a continuous medium establish a relationship between micro and macro characteristics of materials. A mathematical model of thermal conductivity in nonlocal media is considered. The model is based on the theory of nonlocal continuum by A.K. Eringen. The interaction of material particles is described using local and nonlocal terms in the law of heat conduction. The nonlocal term describes the effect of decreasing the influence of the surrounding elements of the material structure with increasing distance. The effect of nonlocal influence is described using the standard non-locality function based on the Gaussian distribution. The nonlocality function depends on the distance between the elements of the material structure. The mathematical model of heat conduction in a nonlocal medium consists of an integro-differential heat conduction equation with initial and boundary conditions. A numerical solution to the problem of heat conduction in a nonlocal plate is obtained. The numerical solution of a two-dimensional problem based on the finite element method is described. The influence of nonlocal effects and material parameters on the thermal conductivity in a plate under highintensity surface heating is analyzed. The importance of nonlocal characteristics in modelling the thermodynamic behaviour of materials with a complex structure is demonstrated.

Numerical Simulation of Heat, Air, and Moisture Transfer Through a Wall of Porous Media

2020 ◽  
Author(s):  
Kiflom B. Tesfamariam ◽  
Cheng-Xian (Charlie) Lin ◽  
Fang Liu
Keyword(s):  
Numerical Simulation ◽  
Moisture Transport ◽  
Moisture Transfer ◽  
Simulation Software ◽  
Transport Processes ◽  
Two Dimensional ◽  
Heat And Moisture Transfer ◽  
Porous Walls ◽  
Heat And Moisture ◽  
Benchmark Solutions

Abstract This paper presents the results of two-dimensional (2D) numerical simulation of heat, air, and moisture transfer through porous walls, which have important application background in the built environment and other engineering fields. The air flows, heat and moisture transfer in the walls are studied using a transient heat, air, and moisture (HAM) model. This model treats the non-isothermal airflow through two-dimensional porous geometries in a time-dependent format. The model includes the Brinkman equation describes the flow of air and other mathematical equations that calculate the heat and moisture transfer through the porous region. The equations are solved by a finite element method (FEM) using physics-based modeling, which is implemented in the commercial simulation software, COMSOL Multiphysics. The model prediction is first validated by using published benchmark solutions. Eventually, the numerical results are presented to illustrate the complex effects of material porosity and permeability on the heat and moisture transport, and moisture content variation in space and time through the walls, at different humidity and temperature conditions. Within the investigated parameter ranges, it is demonstrated that the relative humidity and temperature difference are the driving forces for the transient heat, air, and moisture transport processes through the porous area in the porous walls.

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