Numerical study of heat and moisture transport through concrete at elevated temperatures

2014 ◽  
Vol 28 (5) ◽  
pp. 1967-1977 ◽  
Author(s):  
Arul Peter ◽  
Krishnan Murugesan ◽  
UmeshKumar Sharma ◽  
Puneet Arora
Keyword(s):  
Moisture Transport ◽  
Elevated Temperatures ◽  
Numerical Study ◽  
Heat And Moisture Transport ◽  
Heat And Moisture

scholarly journals Heat and Moisture Transport in Multi-Layer Walls: Interaction and Heat Loss at Varying Outdoor Temperatures / Siltuma Un Mitruma Pārnese Caur Daudzslāņainām Būvkonstrukcijām: Āra Temperatūras Izmaiņu Ietekme Uz Siltuma Zudumiem Iekštelpā

2012 ◽  
Vol 49 (6-I) ◽  
pp. 32-43 ◽  
Author(s):  
A. Ozolinsh ◽  
A. Jakovich
Keyword(s):  
Mathematical Model ◽  
Energy Efficiency ◽  
Moisture Transport ◽  
Heat Losses ◽  
Condensate Formation ◽  
Heat And Moisture Transport ◽  
U Value ◽  
Technical Solutions ◽  
Heat And Moisture ◽  
Humidity Profiles

Abstract The heat and moisture transport in multi-layer walls is analysed for five building units. Using the developed program, a typical of Latvian conditions temperature and relative humidity profiles in multi-layered constructions has been obtained and the indoor heat losses estimated. Consideration is also given to the risk of condensate formation and to the influence of moisture on the U-value. The created mathematical model allows forecasting the energy efficiency and sustainability of different technical solutions as refer to the heat and moisture transport in buildings.

Heat and Moisture Transport Through the Micro-Climate Air Annulus of the Clothing-Skin System Under Periodic Motion

2005 ◽  
Author(s):  
N. Ghaddar ◽  
K. Ghali ◽  
E. Jaroudi
Keyword(s):  
Heat Loss ◽  
Latent Heat ◽  
Moisture Transport ◽  
Contact Region ◽  
Heat Losses ◽  
Sensible Heat ◽  
Skin Contact ◽  
Cylinder Model ◽  
Heat And Moisture Transport ◽  
Heat And Moisture

A dynamic thermal model is developed using the 2D cylinder model of Ghaddar et al [1] of ventilated fabric-skin system where a microclimate air annulus separates an outer cylindrical fabric boundary and an inner human body solid boundary for closed and open apertures. The cylinder model solves for the radial, and angular flow rates in the microclimate air annulus domain where the inner cylinder is oscillating within an outer fixed cylinder of porous fabric boundary. The 2-D cylinder model is further developed in the radial and angular directions to incorporate the heat and moisture transport from the inner cylinder when the fabric touches the skin boundary at repetitive finite intervals during the motion cycle. The touch model is based on a lumped fabric transient approach based on the fabric dry and evaporative resistances at the localized touch regions at the top and bottom of points of the cylinder. The film coefficients at the inner cylinder are needed for the model simulation. Experiments are conducted in an environmental chamber under controlled conditions to measure the mass transfer coefficient at the skin to the air annulus separating the wet skin and the fabric in the cylindrical geometry. In addition, experiments have also been conducted at ventilation frequencies of 30, 40, and 60 rpm to measure the sensible heat loss from the inner cylinder to validate the predictions of sensible and latent heat losses of the 2-D ventilation model for the two cases when fabric is in contact with the skin surface and when no contact is present for close aperture. The model prediction of time-averaged steady-periodic sensible heat loss agreed well with the experimentally measured values. A parametric study is performed to predict sensible and latent heat losses from the system by ventilation at different frequencies, fabric skin contact times during the motion cycle measured by a dimensionless amplitude parameter (ζ = amplitude/mean annular spacing). The rate of heat loss increases with increased ventilation frequency at fixed ζ. The latent heat loss in the contact region increases by almost 40% due to increase in fabric temperature during contact. The sensible heat loss decreases between 3% at f = 60 rpm, and 5% at f = 25 rpm in the contact region due to higher air temperature and lack of heat loss by radiation during the contact between fabric and skin.

scholarly journals Atmospheric heat and moisture transport to energy‐ and water‐limited ecosystems

2020 ◽  
Vol 1472 (1) ◽  
pp. 123-138
Author(s):  
Dominik L. Schumacher ◽  
Jessica Keune ◽  
Diego G. Miralles
Keyword(s):  
Moisture Transport ◽  
Heat And Moisture Transport ◽  
Atmospheric Heat ◽  
Heat And Moisture
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