碩士 / 國立成功大學 / 機械工程學系 / 106 / This study uses three-dimensional computational fluid dynamics (CFD) numerical simulation along with inverse method and experimental temperature data to investigate the mixed convection heat transfer and flow characteristics of H-type finned tube heat exchanger in a rectangular tunnel. The effects of three parameters including inlet velocity Va, fin spacing S and fin length L are examined. The inverse method in conjunction with finite difference method and least-squares scheme are applied to predict the heat transfer characteristics, then compare those with the existing correlations, utilize the non-linear regression technique to obtain the practical correlation for Nusselt number, which is in good agreement with the inverse results. The temperature contour, streamline and heat transfer characteristics are determined by CFD. In order to obtain more accurate and reliable numerical results, the selection of flow models and mesh system must match temperature data and inverse results. It is found that enhanced realizable k-ε turbulence model is more suitable for higher inlet velocity than RNG k-ε. With the increase of inlet velocity and fin spacing, or the decrease of fin length, the heat transfer coefficient increases. The H-type finned tube is performed with an improvement of the heat transfer coefficient by 18.4%. Finally, the thermal-and-flow mechanism of the local heat transfer enhancement around the groove can be observed.
| Identifer | oai:union.ndltd.org:TW/106NCKU5489043 |
| Date | January 2018 |
| Creators | Yao-LunChang, 張耀倫 |
| Contributors | Han-Taw Chen, 陳寒濤 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 143 |
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