RT Journal Article ID 46c1740b3d062cd5 A1 Wang, Han A1 Sun, Chuang A1 Xia, Xin-Lin T1 EXPERIMENTAL RESEARCH ON COUPLED HEAT TRANSFER OF A HEAT SOURCE ENCAPSULATED INTO A SUBATMOSPHERIC HYPOBARIC CHAMBER JF Heat Transfer Research JO HTR YR 2015 FD 2015-09-01 VO 46 IS 12 SP 1065 OP 1079 K1 low pressure K1 variable property K1 coupled heat transfer K1 natural convection AB In this work, an experimental setup was built to measure the coupled heat transfer mechanism of natural convection and radiation in a low-pressure enclosure with a heating cubic element, in which the pressure varied from 90 kPa to 0.1 kPa. The cubic element was heated by six attached electrical heating plates. An infrared thermography was used to measure the wall emissivities, based on which the net heat radiation flux between the component and hypobaric chamber was calculated by the Monte Carlo method. Eventually, the relative magnitude of natural convection and surface radiation can be estimated in the form of heat flux ratio, which was useful for better understanding the heat exchanger process in the low pressure environment. Experimental results provided the temperature distribution on the surface of the element, and heat dissipation was demonstrated. Considering the variable density of air at a low pressure, the average Nusselt numbers in the above pressure range could be correlated well with the Rayleigh number into three correlations, providing valuable reference for the engineering design calculations and thermal analysis. PB Begell House LK https://www.dl.begellhouse.com/journals/46784ef93dddff27,1e9410bc3b20e983,46c1740b3d062cd5.html