[의류제품] Simplified Heat Transport Model of a Wind-permeable Clothed Cylinder Subject to Swinging Motion 출판일 : 2009.07.01 저자 : K. Ghali, M. Othmani, B. Jreije, N. Ghaddar 서지사항 : Textile Research Journal, Volume 79, Issue 11, 1043페이지 등록일 : 2011.05.30 I 조회수 : 111 작성자 : admin |
The effect of ventilation induced by the swinging motion of a clothed cylinder in uniform wind
derived from Ghaddar et al.'s periodic ventilation model is incorporated into Lotens' simple
heat resistance network model to predict the mean steady periodic heat loss from the
clothed cylinder. Experiments are conducted to measure the sensible heat loss from the
inner cylinder for the case of a swinging inner cylinder enclosed within a clothed cylinder at
different frequencies of motion and for open and closed clothing apertures at the one end of
the clothed cylinder. The heat model predictions of time-averaged steady-periodic sensible
heat loss agree well with the experimentally measured values at different swing frequencies
between 40 and 80 rpm from experiments conducted in a controlled environmental chamber
at T ∞ = 25°C and relative humidity (RH) = 50% (air velocity is less than 0.05 m/s) and in a
low-speed wind tunnel (for air speed between 2 and 4 m/s). The model results showed
that the rate of heat loss increased with increased ventilation frequency. Heat transfer by
ventilation presented more than 50% of total heat loss from a clothed cylinder at f = 80 rpm in
the absence and presence of wind. When accurate ventilation rates of clothed swinging
cylinder are estimated from first principles, the simplified heat resistance model predicted
the heat loss from the isothermal cylinder surface with reasonable accuracy. The model will
be a convenient tool for predicting segmental walking human body heat losses.
|