The Numerical Simulation Computational Model of Dynamic Heat and Moisture Transfer in Fibrous Insulation

2007 ◽  
Author(s):  
Ruomei Wang ◽  
Yi Li ◽  
Xiaonan Luo ◽  
Pingchang Zhang ◽  
Theodore E. Simos ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Computational Model ◽  
Moisture Transfer ◽  
Heat And Moisture Transfer ◽  
Fibrous Insulation ◽  
Heat And Moisture

scholarly journals Modification of building energy simulation tool TRNSYS for modelling nonlinear heat and moisture transfer phenomena by TRNSYS/MATLAB integration

2020 ◽  
Vol 172 ◽  
pp. 25009
Author(s):  
Ajaya Ketan Nayak ◽  
Aya Hagishima
Keyword(s):  
Numerical Simulation ◽  
Moisture Transfer ◽  
Ambient Air ◽  
Building Energy ◽  
Energy Simulation ◽  
Modular Structure ◽  
Integration Scheme ◽  
Building Energy Simulation ◽  
Heat And Moisture Transfer ◽  
Heat And Moisture

Software for numerical simulation of various types of energy used in buildings, i.e. building energy simulation (BES), have become an essential tool for recent research pertaining to building physics. TRNSYS is a well-known BES used in both academia and the construction industry for a wide range of simulations, such as the design and performance evaluation of buildings and related facilities for heating, cooling, and ventilation. TRNSYS has a modular structure comprising various components, and each component is interconnected and compiled through a common interface using a FORTRAN compiler. Its modular structure enables interactions with various external numerical simulation tools, such as MATLAB, Python, and ESP-r. For ordinary simulations of building energy load using TRNSYS, the generic module Type 56 is usually recommended, which provides detailed physics modelling of building thermal behaviours based on unsteady energy conservation equations and Fourier’s law for each building material. However, Type 56 explicitly depends on the transfer function method to discretise the original differential equations; therefore, it cannot model nonlinear phenomena, such as latent heat and moisture transfer between a building surface and ambient air. In other words, the current TRNSYS cannot be used to estimate the effectiveness of evaporation during cooling, which is a typical passive design method. Hence, the authors developed a MATLAB/TRNSYS integration scheme, in which TRNSYS was modified to model simultaneous heat and moisture transfer from the wet roof surface of a building. This scheme enabled TRNSYS to calculate the rate of evaporative heat and moisture transfer dynamically from the roof surface, assuming a control volume approximation of the roof surface. Finally, the effect of evaporative cooling on the thermal performance of an Indian building was estimated using the modified model.

A Numerical and Experimental Study of Heat and Moisture Transfer With Phase Change and Mobile Condensates in Fibrous Insulation

2003 ◽  
Author(s):  
Jintu Fan ◽  
Xiaoyin Cheng
Keyword(s):  
Phase Change ◽  
Moisture Absorption ◽  
Moisture Transfer ◽  
Water Vapor Pressure ◽  
Heat And Moisture Transfer ◽  
Moisture Movement ◽  
Saturation State ◽  
New Model ◽  
Fibrous Insulation ◽  
Heat And Moisture

This paper reports on an improved model of coupled heat and moisture transfer with phase change and mobile condensates in fibrous insulation. The new model considered the moisture movement induced by the partial water vapor pressure, a super saturation state in condensing region as well as the dynamic moisture absorption of fibrous materials and the movement of liquid condensates. The results of the new model were compared and found in good agreement with the experimental ones. Numerical simulation was carried using the model to investigate the effect of various material parameters on the transport phenomena.

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.

Numerical Simulation of Hygro-Thermal Deformation of Concrete Based on Heat and Moisture Transfer

2010 ◽  
Vol 129-131 ◽  
pp. 179-184
Author(s):  
De Peng Chen ◽  
Chun Lin Liu ◽  
Chun Xiang Qian
Keyword(s):  
Numerical Simulation ◽  
Life Prediction ◽  
Thermal Deformation ◽  
Analytic Solution ◽  
Moisture Transfer ◽  
Heat And Moisture Transfer ◽  
Element Analysis ◽  
Moisture Condition ◽  
Heat And Moisture ◽  
Visual Basic 6.0

Concrete deformation due to temperature and moisture condition will always develop simultaneously and interactively. The numerical simulation of hygro-thermal deformation of concrete is necessary to be investigated for better serviceability, durability estimation and life prediction. In this paper, a numerical simulation procedure was proposed for hygro-thermal deformation of concrete based on the principle of heat and moisture transfer in porous medium. The procedure comprised an analytic solution of heat and moisture transfer, a calculation of moisture induced stress and a finite element analysis (FEM) of hygro-thermal deformation. The methodology of a software named Coupling Temperature and Moisture Simulation System for concrete (CTMSoft) was represented and developed by a mix programming. The graphical user interface (GUI) of the software was programmed by Visual Basic 6.0 and its real numerical calculation process was conducted by calling Matlab and ANSYS. The efficiency of the CTMSoft was validated by a case analysis of the data of Hundt’s test.

Sign in / Sign up

Export Citation Format

Share Document