Number：

04095009

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Name：

曾憲中

Titles：

Associate professor

Author：

Tzer-Ming Jeng , Sheng-Chung Tzeng , Dong-Chun Liu

Paper name：

Rotating effect on Heat transfer enhancement of combining metallic porous heat sink and impinging jet

Name of activity：

中國機械工程學會第二十三屆全國學術研討會論文集

Keywords：heat transfer, jet impingement, al-foam heat sink, rotation

Abstract：This work experimentally investigated the heat transfer enhancement of jet impingement onto the rotating heat sink. Air was used as impinging coolant, while a square al-foam heat sink with 0.93 porosity (ε), 10 PPI (pores per inch) and L/d=2:222 (L/d is the relative side length of the square heat sink) was employed. Variable parameters were the jet Reynolds number (Re), the relative distance of nozzle-to-foam tip (C/d) and the rotational Reynolds number (Re_r). The effects of Re, C/d and Re_r on the average Nusselt number were presented. For a stationary system, the results indicate that the average Nusselt number (Nu₀) with al-foams was 2-3 times without al-foams. And, there was a large Nu₀ for the bigger Re. Theeffect of C/d on Nu₀ was insignificant. For a rotating system, when Re was small and C/d was large, Re_r would significantly promote the average Nusselt number (Nu_Ω). Furthermore, according to the base of Nu_Ω/ Nu₀ ≧1.1 the results suggest that the substantial rotation appeared at Re_r /Re ≧1.44 for the case of C/d=0 and the rotation was always substantial for cases of C/d≧1.

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