scholarly journals Influence of washing on textile material thermal properties under exposure of an open flame and heating ele-ment heat flow

2021 ◽  
Vol 54 (4) ◽  
pp. 10-15
Author(s):  
Alexander N. Petukhov ◽  
Alexander F. Davydov
Keyword(s):  
Heat Transfer ◽  
Convective Heat ◽  
Protective Clothing ◽  
Elevated Temperatures ◽  
Heating Element ◽  
Textile Material ◽  
Radiant Heat Transfer ◽  
Open Flame ◽  
Heat Shielding ◽  
Transfer Index

Elevated temperatures are factors causing harm to human health and life. To ensure protection, various personal protective equipment is used, which includes special protective clothing. The article discusses the heat-shielding indicators of the safety of textile material. In order to determine the heat-shielding properties of the material, various types of exposure are used – convective heat from a heating element and an open flame. Fabrics of various raw materials and surface density are used for sewing special protective clothing. Five clothes were selected for the research. The research was held under the exposure of an open flame and convective heat of heating element with a comparable heat flux density equal to 80 kW/m². Also, research was held under influence of multiple wash cycles on radiant heat transfer index and heat transfer index.

A Numerical Study of the Effect of an Irradiated Slatted Top Down – Bottom Up Blind on the Convective Heat Transfer Rate From a Recessed Window to an Adjacent Room

2012 ◽  
Author(s):  
Patrick H. Oosthuizen ◽  
J. T. Paul
Keyword(s):  
Heat Transfer ◽  
Convective Heat Transfer ◽  
Heat Transfer Rate ◽  
Convective Heat ◽  
Transfer Rate ◽  
Numerical Study ◽  
Solar Irradiation ◽  
Radiant Heat Transfer ◽  
Top Down ◽  
Bottom Up

Top Down – Bottom Up blinds have become quite popular in recent times. However the effects of such blind systems on the convective heat transfer from the window to the surrounding room have not been extensively studied and the effect of solar irradiation of the blind on the window heat transfer has not received significant attention. The purpose of the present work was therefore to numerically investigate the effect of solar irradiation of Top Down – Bottom Up slatted blinds on this convective heat transfer. An approximate model of the window-blind system has been adopted. The solar radiation falling on the blinds is assumed to produce a uniform rate of heat generation in the blind. The Boussinesq approximation has been used. Radiant heat transfer effects have been neglected. Conditions under which laminar, transitional and turbulent flows occur have been considered. The main emphasis is on the effect of the magnitude of the irradiation and of the size of the blind openings at the top and bottom of the window on the convective heat transfer rate from the window to the room.

Study on the Laminar Mixed Convective Heat Transfer in Three-Dimensional Channel With a Thermal Source

1991 ◽  
Vol 113 (1) ◽  
pp. 40-49 ◽  
Author(s):  
Heiu-Jou Shaw ◽  
Wen-Lih Chen ◽  
Cha’o-Kuang Chen
Keyword(s):  
Heat Transfer ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Three Dimensional ◽  
General Purpose ◽  
Heating Element ◽  
Thermal Source ◽  
Simpler Algorithm ◽  
Alternating Direction ◽  
General Purpose Computer

In this paper, the mixed convective heat transfer phenomena in a three-dimensional channel with one heating-element is studied. A general-purpose computer program is developed to analyze the flow field and temperature distribution in the channel. In order to ensure the accuracy of result, numerical computation is performed by using the alternating direction implicit (A.D.I.) method based on the SIMPLER algorithm. This paper deals with fundamental heat transfer phenomena in “L.S.I.” package, which is used extensively in microelectronic equipment. The influences of Reynolds number and Grashof number on the Nusselt number of the heating-element are discussed. In order to make it easier for readers to understand the phenomena studied in this paper, three-dimensional streaklines and three-dimensional isothermal surfaces are presented.

Effect of heat shielding on convective and evaporative heat losses and on radiant heat transfer in the premature infant

1981 ◽  
Vol 99 (6) ◽  
pp. 948-956 ◽  
Author(s):  
Stephen Baumgart ◽  
William D. Engle ◽  
William W. Fox ◽  
Richard A. Polin
Keyword(s):  
Heat Transfer ◽  
Premature Infant ◽  
Radiant Heat ◽  
Heat Losses ◽  
Radiant Heat Transfer ◽  
Heat Shielding

scholarly journals Neural network based thermal protective performance prediction of three-layered fabrics for firefighter clothing

2019 ◽  
Vol 70 (01) ◽  
pp. 57-64
Author(s):  
DURSUN MÜGE ◽  
ŞENOL YAVUZ ◽  
BULGUN ENDER YAZGAN ◽  
AKKAN TANER
Keyword(s):  
Neural Network ◽  
Heat Transfer ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Heat Transfer Performance ◽  
Radiant Heat ◽  
Radiant Heat Transfer ◽  
Transfer Performance ◽  
Layered Fabric ◽  
Protective Performance

The firefighter protective clothing is comprised of three main layers; an outer shell, a moisture barrier and a thermal liner. This three-layered fabric structure provides protection against the fire and extremely hot environments. Various parameters such as fabric construction, weight, warp/weft count, warp/weft density, thickness, water vapour resistance of the fabric layers have effect on the protective performance as heat transfer through the firefighter clothing. In this study, it is aimed to examine the predictability of the heat transfer index of three-layered fabrics, as function of the fabric parameters using artificial neural networks. Therefore, 64 different three layered-fabric assembly combinations of the firefighter clothing were obtained and the convective heat transfer (HTI) and radiant heat transfer (RHTI) through the fabric combinations were measured in a laboratory. Six multilayer perceptron neural networks (MLPNN) each with a single hidden layer and the same 12 input data were constructed to predict the convective heat transfer performance and the radiant heat transfer performance of three-layered fabrics separately. The networks 1 to 4 were trained to predict HTI12, HTI24, RHTI12, and RHTI24, respectively, while networks 5 and 6 had two outputs, HTI12 and HTI24, and RHTI12 and RHTI24, respectively. Each system indicates a good correlation between the predicted values and the experimental values. The results demonstrate that the proposed MLPNNs are able to predict the convective heat transfer and the radiant heat transfer effectively. However, the neural network with two outputs has slightly better prediction performance

Experimental Description of the Convective Heat Transfer Coefficient for Pool Boiling of Binary Mixtures on Porous Heating Surfaces

2003 ◽  
Author(s):  
Elva Mele´ndez ◽  
Rene´ Reyes
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Convective Heat Transfer ◽  
Binary Mixtures ◽  
Convective Heat ◽  
Pure Water ◽  
Convective Heat Transfer Coefficient ◽  
Heating Element ◽  
Heating Surfaces

This work presents the experimental results of the effect of porous heating surfaces, and the Marangoni effect on the convective heat transfer coefficient for pool boiling, h. The porous heating surfaces fabricated for these experiments, and the interfacial tension gradients in the binary mixtures reduced the bubbles’ size and their coalescence in the proximity of the heating surface. The convective heat transfer coefficient was calculated for the boiling of pure water and three aqueous mixtures with 12, 16, and 20% weight of ethanol on five different porous coverings on the heating element. Some combinations of these variables were studied in a 32 factorial design, and represented by the response surface calculated. The maximum h for boiling of pure water on the bare surface of the heating element was 50 kW/m2 °C. Using the porous coverings, the maximum h value was 180 kW/m2 °C. For boiling the binary mixtures on the smooth heating element surface the maximum h value was 65 kW/m2 °C, while on the porous coverings the values of h attained a maximum of 220 kW/m2 °C. The maximum values of h correspond to the composition of 16% ethanol, and a porous covering with the smallest porous diameter.

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