Raditation Analysis in a closed curved surface with a heat source

• Main Authors: Lai Ching Feng, 賴慶峰
• Other Authors: Wang Muh Rong
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/36186861196983497736

碩士 === 國立成功大學 === 航空太空工程學系 === 89 === The research is to investigate the distribution of the radiation energy and the heat transfer mechanisms of an enclosure with heat source. We use Data Model Hd9221 Photo-Radiometer to measure the radiation of a heat source and the enclosure surface. We use K-type thermocouple and Inframetrics Model-60 IR Imager to measure the closed surface temperature of the enclosure. The temperature distribution of the flow field inside the enclosure is also measured. Results shows that radiation in visible range is higher for the case with high beam and low beam design. Foe example, visible radiation up to 30﹪of the total radiation is measure in the design with high beam and low beam together, while the visible radiation is only 10﹪for the case without high beam./low beam design .It is attributed to the spectrum of the source radiation, absorption and reflection of the material. Results also show that total radiation and the heat flux increase as the power of the heat source increases. However, there are two peaks of radiations in the vertical plane passing through the axis of the heat source, with the maximum radiation takes place at θ= -750. It is also found that the temperature distribution of the flow inside the enclosure is effected by the internal structure of the heat source. For example, there is a supporting wire above the heating element of the 9007 heat source and it results in a blockage effect on the radiation from the heating element, while the H-4 heat source has not such kind of mechanism. Hence the peak temperature of the hot plume from the H-4 heat source is at the center while those of the 9007 heat source are on the two side of the hot plume. The energy is then transferred to the outer surface of the heat source through conduction. The air near the outer surface of the heat source is heated up and results in a hot plume above the heat source. The energy is transferred to the inner surface of the enclosure by natural convection. The energy is transferred to the outer surface of the enclosure again by heat conduction and is further transferred to the air outside the enclosure . It is also found that the radiation heat transfer from the heat source to the enclosure can not be neglected temperature is as high as 580℃.