Electric circuit analogy of heat losses of clothed walking human body in windy environment

2018 ◽  
Vol 127 ◽  
pp. 105-116 ◽  
Author(s):  
Nagham Ismail ◽  
Nesreen Ghaddar ◽  
Kamel Ghali
Keyword(s):  
Human Body ◽  
Electric Circuit ◽  
Heat Losses ◽  
Circuit Analogy

A Novel Modeling Approach to Estimate Segmental and Intersegmental Ventilation and Heat Transport From a Walking Clothed Human Using Electric Circuit Analogy

2017 ◽  
Author(s):  
Nagham Ismail ◽  
Nesreen Ghaddar ◽  
Kamel Ghali
Keyword(s):  
Heat Transport ◽  
Human Body ◽  
Electric Circuit ◽  
Heat Losses ◽  
The Body ◽  
Effective Model ◽  
Sensible Heat ◽  
Body Experiences ◽  
Circuit Analogy ◽  
Relative Wind

When the clothed human body experiences relative wind due to walking and external wind, heat and vapor transfers from the body to the environment are enhanced by ventilation through clothing. The clothing ventilation is related to the clothing permeability, open and close apertures, relative wind, clothed limbs swinging motion as well as the inter-segmental ventilation that occurs at the interconnection between the clothed human trunk and arms. In this study, a computationally effective model is developed to estimate clothing ventilation based on the analogy between the air flow in the microclimate air layer and an electric circuit composed of resistance and inductance elements. The model takes into account the inter-connection between the segments for the clothed human upper part driven by difference of pressure in the microclimate air of the trunk and the upper arms. The estimation of the segmental ventilation, taking into account the inter-connection, allows the correction of the clothing dry resistances in a bio-heat model that will be used to predict the sensible heat losses of the clothed human.

scholarly journals Effect of Slit Channel Width of a Shim Embedded in Slot-Die Head on High-Density Stripe Coating for OLEDs

Coatings ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 772
Author(s):  
Dongkyun Shin ◽  
Jinyoung Lee ◽  
Jongwoon Park
Keyword(s):  
Electric Circuit ◽  
Electrical Circuit ◽  
High Density ◽  
Voltage Source ◽  
Light Emitting ◽  
Slot Die ◽  
Potential Applications ◽  
Circuit Analogy ◽  
Wide Slit ◽  
Fine Organic

With an attempt to achieve high-density fine organic stripes for potential applications in solution-processable organic light-emitting diodes (OLEDs), we have performed slot-die coatings using a shim with slit channels in various shapes (rectangular-shaped narrow, rectangular-shaped wide, and reversely tapered channels) in the presence of narrow µ-tips. Based on hydraulic-electric circuit analogy, we have analyzed the fluid dynamics of an aqueous poly (3,4-ethylenedioxythiophene): poly (4-styrenesulfonate) (PEDOT:PSS). It is observed that the coating speed can be increased and the stripe width can be reduced using a shim with rectangular-shaped wide slit channels. It is attributed that the hydraulic resistance is decreased and thus more fluid can reach a substrate through µ-tips. This behavior is consistent with the simulation result of the equivalent electrical circuit with a DC voltage source representing a pressure source. Using the shim with 150-µm-wide slit channels, we have successfully fabricated 200 PEDOT:PSS stripes within the effective coating width (150 mm) and 160 OLED stripes (34 stripes per inch) with the luminance of 325 cd/m2 at 5 V.

scholarly journals Comprehensive model of upper human body clothing ventilation in standing and walking conditions

2018 ◽  
Vol 13 (4) ◽  
pp. 155892501882072
Author(s):  
Nagham Ismail ◽  
Nesreen Ghaddar ◽  
Kamel Ghali
Keyword(s):  
Human Body ◽  
Relative Velocity ◽  
Air Flow ◽  
Electric Circuit ◽  
Maximum Error ◽  
Body Parts ◽  
Tracer Gas ◽  
Physical Boundary Condition ◽  
Experimental Values ◽  
Physical Boundary

The ventilation of the microclimate air of the clothed human body segment is a result of (1) the air flow from the environment through the clothing open apertures, (2) the penetration of the porous clothing, or (3) air flow originating in the microclimate of the other clothed body parts. The microclimate air flow at the connections of clothed segments is named the inter-segmental ventilation and constitutes a real physical boundary condition that leads to ventilation of connected segments. In this study, a simplified electric circuit model is developed to estimate clothing ventilation based on the analogy between the air flow in the microclimate air layer and an electric circuit composed of resistance and inductance elements. The model takes into account the inter-connection between the segments for the clothed human upper part driven by difference of pressure in the microclimate air of the trunk and the upper arms. The developed model is validated using the tracer gas method applied on a walking manikin placed in a climatic chamber under windy conditions. Good agreement was found between predicted segmental ventilation and the experimental values with a maximum error of 16%. It was found that the inter-segmental ventilation is significant at high relative velocity for permeable clothing and increased with the increase in the relative velocity constituting about 30% of the arm ventilation and 14% of the trunk ventilation.

THE INFLUENCE OF AIR MOVEMENT UPON HEAT LOSSES FROM THE CLOTHED HUMAN BODY

1939 ◽  
Vol 127 (3) ◽  
pp. 505-518 ◽  
Author(s):  
C. -E. A. Winslow ◽  
A. P. Gagge ◽  
L. P. Herrington
Keyword(s):  
Human Body ◽  
Heat Losses ◽  
Air Movement

Generalized Vibration Analysis by Means of the Mechanical Transients Analyzer

1947 ◽  
Vol 14 (2) ◽  
pp. A127-A134
Author(s):  
G. D. McCann ◽  
J. M. Kopper
Keyword(s):  
Translational Motion ◽  
Mechanical Vibration ◽  
Electric Circuit ◽  
Generalized Solutions ◽  
Wide Range ◽  
Fixed Base ◽  
Vibration Problems ◽  
Circuit Analogy ◽  
Mass Spring ◽  
Curve Form

Abstract This paper presents the results of a general study that has been made of a linear system having 2 deg of freedom. This is representative for many mechanical vibration problems as well as for problems of other physical systems. The system is described specifically in terms of the mechanical parameters of translational motion and consists of one mass, spring, dashpot system mounted on another. Three types of generalized solutions are given for the maximum motion of the first system relative to the second, or the maximum stress developed in the spring of the first system. One of these is for known sinusoidal forces applied to the second system, one is for the whole system striking a fixed base at a known velocity without rebound, and one is for such an impact and one rebound. The solutions were obtained on the mechanical transients analyzer which employs the principle of electric-circuit analogy. The solutions are given in dimensionless curve form for a wide range of all parameters.

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