Analysis for thermal interaction of two different heat transfer systems on both sides of a vertical plate

• Main Authors: Shiuh-Ming Chang, 張旭銘
• Other Authors: Han-Taw Chen
• Format: Others
• Language: zh-TW
• Published: 1995
• Online Access: http://ndltd.ncl.edu.tw/handle/44769978733236526436

博士 === 國立成功大學 === 機械工程研究所 === 83 === Analysis for thermal interaction of two different heat transfer systems on both sides of a vertical plate is presented now. The present investigation includes: (1)The prediction of the heat transfer rate between two natural convection systems at different temperatures. (2)The prediction of the heat transfer rate between laminar film condensation of a saturated vapor and natural convection. (3)The prediction of the heat transfer rate between laminar film condensation of a saturated vapor and forced convection. (4)The prediction of the heat transfer rate between laminar film condensation of a saturated vapor and turbulent mixed convection. (5)The prediction of the heat transfer rate between laminar film condensation in the presence of a noncondensable gas and natural convection. But, in previous similar papers, the value of the cold fluid Prandtl number was assumed to approach infinite, so the effect of Prandtl number was neglected. The numerical results show that ： (1)The present results calculated by one dimensional heat conduction model are in good agreements with experimental results.(2)In some conditions, the effect of the cold fluid Prandtl number could not be negligible. (3)As Ja<1, Nusselt- Rohsenow film condensation model is suitable. On the other hand, when Ja>1 (liquid FC-70R, Ja=3), the numerical solutions calculated by Nusselt-Rohsenow model are lower than the experimental results. (4)For Chapter 3 and 4,increasing Reynolds number Rec can decrease the wall temperature. (5)The presence of a very small amount of a noncondensable gas in the bulk of the vapor could cause a large buildup of the noncondensable gas at the liquid-vapor interface, so the temperature at the interface would decrease. It is worth memtioning that the interface temperature is not equal to wall temperature.