碩士 / 建國科技大學 / 自動化工程系暨機電光系統研究所 / 95 / This study used steady-state experiment to discuss the presence of forced convection characteristic of in-channel square pin-fin heat sink at the top bypass. The aluminum alloy square pin-fin heat sink has different relative axial and transverse distances against the square pin-fin (XL = 3.115, 2.073, 1.552; XT = 3.115, 2.073, 1.552). A total of three combinations of relative distance were tested. The range of change for the ratio of top bypass to pin-fin height is C/H = 0.3, 0.6, 1.0, that for Reynold number is 592 ≤ Re ≤ 6394. The results showed that the average Nusselt number increases as the Reynold number increases, and decreases as the relative transverse distance against the square pin-fin (XT) decreases. Under comparison, the relative axial distance (XL) has insignificant effect on Nu. When the top bypass is larger, Nu decreases, and the magnitude of decrease increases as the relative distances (XT, XL) decrease. Friction coefficient (ƒ) is subject to shape resistance, thus, ƒ is proportional to the square of Re. Also, ƒ increases as the relative transverse distance decreases, and the relative axial distance increases. When the top bypass is larger, ƒ decreases, and the magnitude of decrease increases as the relative distances (XT, XL) decrease. Lastly, modification of empirical formula of average Nu to Re for in-channel square pin-fin heat sink, and relation of average Nu to dimensionless air blast power parameter (ƒRe3), are proposed. It was found that under the same blast power, smaller relative axial and transverse distances against the square pin-fin would generate better Nu, and the relation between ƒRe3 and Nu is only correlated with the interval between the pin-fin, and is not correlated with the top bypass.
| Identifer | oai:union.ndltd.org:TW/095CTU05790019 |
| Creators | Yung-Chih Tsao, 曹詠植 |
| Contributors | Sheng-Chung Tzeng, 曾憲中 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 78 |
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