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.

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.

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

L[sup 1]-Uniqueness of Weak Solution for One-Dimensional mass Transport Equation

2009 ◽  
Author(s):  
Ludovic Dan Lemle ◽  
Tudor Bi^nzar ◽  
Flavius Pater ◽  
Theodore E. Simos ◽  
George Psihoyios ◽  
...  
Keyword(s):  
Weak Solution ◽  
Mass Transport ◽  
Transport Equation ◽  
One Dimensional ◽  
Mass Transport Equation

scholarly journals On the Generalized Mass Transport Equation to the Concept of Variable Fractional Derivative

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Abdon Atangana ◽  
Adem Kilicman
Keyword(s):  
Mass Transport ◽  
Fractional Derivative ◽  
Numerical Simulations ◽  
Transport Equation ◽  
Stability And Convergence ◽  
Hydrodynamic Dispersion ◽  
The Stability ◽  
Mass Transport Equation ◽  
Modified Equation ◽  
Convergence Of The Scheme

The hydrodynamic dispersion equation was generalized using the concept of variational order derivative. The modified equation was numerically solved via the Crank-Nicholson scheme. The stability and convergence of the scheme in this case were presented. The numerical simulations showed that, the modified equation is more reliable in predicting the movement of pollution in the deformable aquifers, than the constant fractional and integer derivatives.

Modelling of Double Diffusion in Turbulent Mass Transport in Porous Media

Volume 1 ◽  
2004 ◽  
Author(s):  
Marcelo J. S. de Lemos
Keyword(s):  
Mass Transport ◽  
Transport Equation ◽  
Fluid Phase ◽  
Double Diffusion ◽  
Time Averaging ◽  
Turbulent Regime ◽  
Transport Mechanisms ◽  
Driving Mechanisms ◽  
Mass Fluxes ◽  
Mass Transport Equation

This work presents derivations of macroscopic heat and mass transport equations for turbulent flow in permeable structures. Two driving mechanisms are considered to contribute to the overall momentum transport, namely temperature driven and concentration driven mass fluxes. Double-diffusive natural convection mechanism is investigated for the fluid phase in turbulent regime. Equations are presented based on two distinct procedures. The first method considers time averaging of the local instantaneous mass transport equation before the volume average operator is applied. The second methodology employs both averaging operators but in a reverse order. This work is intended to demonstrate that additional transport mechanisms are mathematically derived if temperature, concentration and velocity present simultaneously time fluctuations and spatial deviations within the domain of analysis. A modeled form for the final mass transport equation is presented where turbulent transfer is based on a macroscopic version of the k-ε model.

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