Study on Heat Transfer and Flow Visualization Characteristics of Porous Metallic Heat Sink with Conductive Cylinder under Bypass Effect

• Main Authors: F. Z. Tang, 湯豐彰
• Other Authors: S. C. Tzeng
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/07512709615373658428

碩士 === 建國科技大學 === 自動化工程系暨機電光系統研究所 === 97 === This study experimentally investigated the fluid flow and heat transfer characteristics of the heat sink situated in a rectangular channel with bypass spaces. A novel heat sink, consisting of the metallic porous materials and the high-thermal-conductivity cylinder, was proposed. Air was employed as the coolant. The relevant parameters were the Reynolds number (Re), the relative top bypass space (C/H), and the relative side bypass space (S/L). The novel heat sink, with a size of 60mm (L) × 60mm (L) × 24mm (H), was manufactured by inserting a copper conductive cylinder into the 0.9-porosity aluminum-foam block. Three heat sinks were employed as test specimens: (A) the pure aluminum-foam heat sink, (B) the aluminum-foam heat sink with a 20mm-diameter copper cylinder, and (C) the aluminum-foam heat sink with a 30mm-diameter copper cylinder. Experimental results demonstrate that increasing bypass space decreased the average Nusselt number. Besides, the average Nusselt numbers of mode B and mode C heat sinks were 35% and 27% higher than mode A under the state of non-bypass space, respectively. When the bypass space grew, the effect of the copper cylinder on the fluid flow and heat transfer characteristics would decline.