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초록

Boiling offers superior thermal performance because of its latent heat utilization, and flow boiling, in particular, has been extensively studied for potential in embedded cooling applications. In this study, we conducted two-phase flow boiling experiments using a manifold microchannel (MMC) coated with porous copper inverse opals (CuIO). The MMC has a total base area of 5 × 5 mm2, a PDMS manifold with three inlets and two outlets, and a microchannel unit passage width of 100 μ m. By varying the mass flux conditions from 1000 to 2000 kg/m2 s, we achieved a critical heat flux (CHF) of up to 237 W/cm2 and a heat transfer coefficient (HTC) of approximately 26,000 W/m2 K. As the flow rate increased, the convective thermal resistance was reduced to a minimum of 0.26 cm2K/W. Visualization showed that Novec649, the dielectric working fluid, was vigorously promoted to nucleate by CuIO, eventually resulting in a large amount of vapor occupying the manifold cross-section at high heat flux. The pressure drop increased more rapidly with the onset of nucleation, and continued to rise with increasing mass flux, reaching a maximum of 26.6 kPa at CHF.

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