fabric material properties aaron packard me en 340 heat transfer 16 april 2007
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Fabric Material Properties
Aaron Packard
Me En 340 Heat Transfer
16 April 2007
Introduction
• Body uses evaporative cooling for temperature regulation
• Jersey material influences the effectiveness of evaporative cooling
• Influential factors
– Material conduction coefficient
– Fabric weave and pattern
– Moisture wicking capabilities
• Compared Cotton to Polyester
Heat Transfer Problem
• Calculated convective heat coefficient for free convection
• Thermal conductivity of fabric varies with:
– Material
– Weave and fabric pattern
– Moisture content
• Heat generation of body is dependent on current metabolic rate
Solution
• Difficulty of modeling
• Experimentation
– Measure body surface temperature
– Warm up with heart rate at 153 bpm
– Stop at steady state surface temperature
– Cool down with fan
Results and Conclusions
• Shirt – Less wicking of moisture causes
perspiration to remain closer to the skin and reduces the amount of heat that can be transferred from the surface through evaporative cooling.
• Jersey– Better breath-ability– Wicks moisture and diffuses it
over a greater surface area allowing for more effective evaporative cooling.
Body Surface Temperature
82
84
86
88
90
92
94
96
98
0 100 200 300 400 500 600 700 800 900
Time (Sec)
Tem
pera
ture
(F)
Jersey
T-Shirt