Effects of microchannel manufacturing inaccuracies on heat sink performance: Numerical and experimental investigation

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Makina Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2018

Öğrenci: CANBERK ÖZTOPRAK

Danışman: İLKER TARI

Özet:

Alternative thermal designs of a microwave module constituting six monolithic microwave integrated circuit (MMIC) power amplifiers (PA) chips with total heat dissipation of 195 W is created by applying a single-phase liquid cooling solution with microchannel heat sinks. Four cold plate alternatives are designed with different material selections of copper and aluminum at increasing fin densities of 25 fins per inch and 85 fins per inch. Heat sink performance of the alternative cold plates with microchannels is investigated numerically and experimentally. A post-experiment numerical investigation is performed in order to understand the sources of mismatch between numerical simulations and experimental studies. Detailed inspection of microchannel heat sinks is resulted with detection of manufacturing inaccuracies due to manufacturing limitations. These manufacturing inaccuracies are classified as variations in channel width, channel height and angle of channel inclination. In the post-experimental numerical investigation, these inaccuracies are analyzed for their individual effects on heat sink performance. For the best representation of manufacturing inaccuracies detected in microchannel heat sinks, combinations of the manufacturing inaccuracies are modeled for numerical simulations. The results of the post-experimental numerical simulations resulted in a good match with experimental studies, especially for pressure gradient values. The study shows microchannel heat sink performance variations to be expected with different material selections, different fin densities, and manufacturing inaccuracies. The study concludes with the design considerations are to be taken into account for a successful thermal design with microchannel heat sinks. To the best of authors knowledge, this study is the first in literature specifically focusing on the effects of manufacturing inaccuracies on heat sink performance.