ScholarWorks@중앙대학교

초록

The rapid densification of AI semiconductors and the proliferation of data centers have significantly increased the demand for advanced thermal management solutions. Employing manifold microchannels (MMCs) in two-phase embedded cooling systems has emerged as an effective method to address these thermal challenges. However, a comprehensive understanding of the flow characteristics within these systems remains limited, especially for performance optimization and triggers of critical heat flux (CHF) due to the complex liquid–vapor interactions occurring in three-dimensional cooling structures. This study investigates the flow boiling behavior in MMCs coated with copper inverse opals (CuIOs), utilizing Novec-649 as the working fluid. Experiments are performed at mass fluxes of 1000 and 2000 kg m−2 s−1 within microchannels having aspect ratios of 0.5, 1, and 2. The CuIO coatings enhance nucleate boiling and stabilize liquid film dynamics by providing interconnected porous structures, thus effectively delaying dry-out phenomena, achieving a maximum CHF of 237 W cm−2. Furthermore, the study elucidates flow dynamics linked to heat transfer coefficients, thermal resistance, and mechanisms underlying flow-induced instabilities, emphasizing bubble behavior and its critical role in CHF initiation. In-situ visualization provides direct observations of CHF-triggering mechanisms, including bubble confinement and backflow induced by flow non-uniformity, highlighting that the instability characteristics vary significantly depending on microchannel geometry. These findings contribute critical insights into the two-phase flow phenomena within MMC systems, offering practical guidelines for tailoring channel geometry and surface coatings to enhance thermal management capability in embedded cooling solutions for high heat flux electronic applications.

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