A Coupled Model for Predicting Heat and Mass Transfer from a Human Body to its Surroundings

2003 ◽  
Author(s):  
Ahmed Al-Mogbel ◽  
Sushil Chaturvedi
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Human Body ◽  
Coupled Model

The Passing Behaviors of Vapor through Cloth

2006 ◽  
Vol 128 (8) ◽  
pp. 739-739
Author(s):  
Akira Narumi ◽  
Kenichi Uchida ◽  
Tadashi Konishi
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Measurement Technique ◽  
Human Body ◽  
Holographic Interferometry ◽  
Liquid Surface ◽  
Scientific Research ◽  
Liquid Temperature ◽  
Small Space ◽  
Sweat Evaporation

There occurs heat and mass transfer through cloth in the very small space from skin to the outside of cloth due to the release of heat and sweat evaporation from human body. The new simultaneous 2-D measurement technique of temperature and concentration distributions that combines infrared absorbing method (IR) with holographic interferometry (HI) was applied to this space. Cotton (porosity Φ=0.586, thickness t=324μm) and nylon (Φ=0.578, t=347μm) were used for the typical hydrophilic and hydrophobic clothes, respectively. N-propanol was used for liquid. The distance from liquid surface to cloth was 5mm. Liquid temperature was 40°C. The superimposed images of HI and IR show clearly that more vapor passes through cloth in the case of cotton than in the case of nylon. This fact demonstrates that this new technique is very useful for measuring the passing behaviors of vapor through cloth. We appreciate that this research was partially supported by funds of Grant-in-Aid for Scientific Research in Japan.

Simulation study on the effect of underwear on thermal reaction of human body based on heat and mass transfer theory

2019 ◽  
Vol 29 (12) ◽  
pp. 4724-4745
Author(s):  
Pengpeng Cheng ◽  
Daoling Chen
Keyword(s):  
Mass Transfer ◽  
High Temperature ◽  
Heat And Mass Transfer ◽  
Human Body ◽  
Mass Conservation ◽  
Thermal Reaction ◽  
Content Type ◽  
Human Experiments ◽  
The Individual ◽  
The Impact

Purpose The purpose of this paper is to analyze the influence of underwear on the microenvironment of human clothing. Design/methodology/approach Based on the basic laws of energy and mass conservation, the paper combined the theory of heat and mass transfer to establish the simulation of the influence of underwear on human thermal reaction in microclimate and prediction model of human thermal reaction law. Findings The impact on the microenvironment affected by tighter underwear is less than the effect of loose underwear and computational flow dynamics (CFD) can accurately predict the thermal reaction parameters’ values of the human body. Originality/value It can be effectively used for the prediction of heat exchange between human body and environment in high-temperature environment and human thermophysiological parameters, and overcomes the individual differences of human experiments and the danger and repeatability of high-temperature environmental experiments.

scholarly journals Nonequilibrium Thermal Dynamic Modeling of Porous Medium Vacuum Drying Process

2012 ◽  
Vol 2012 ◽  
pp. 1-22 ◽  
Author(s):  
Zhijun Zhang ◽  
Ninghua Kong
Keyword(s):  
Mass Transfer ◽  
Porous Medium ◽  
Heat And Mass Transfer ◽  
Water Saturation ◽  
Coupled Model ◽  
Water Evaporation ◽  
Vacuum Drying ◽  
Vapor Pressures ◽  
Drying Process ◽  
Medium Vacuum

Porous medium vacuum drying is a complicated heat and mass transfer process. Based on the theory of heat and mass transfer, a coupled model for the porous medium vacuum drying process is constructed. The model is implemented and solved using COMSOL software. The water evaporation rate is determined using a nonequilibrium method with the rate constant parameterKr.  Krvalues of 1, 10, 1000, and 10000 are simulated. The effects of vapor pressures of 1000, 5000, and 9000 Pa; initial moistures of 0.6, 0.5, and 0.4 water saturation; heat temperatures of 323, 333, and 343 K; and intrinsic permeability of 10−13, 10−14, and 10−15 m2are studied. The results facilitate a better understanding of the porous medium vacuum drying process.

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