Phasor-Based Dehomogenisation for Microchannel Cooling Topology Optimisation

Efficient thermal management is critical for highpower electronics, with microchannel cooling providing enhanced heat dissipation in compact designs. Conventional topology optimisation (TO) methods often fail to capture fine-scale features without relying on extremely fine meshes, leading to high computational costs. This study proposes a homogenisationbased TO framework integrated with an on-the-fly phasorbased dehomogenisation technique. The phasor-based method efficiently maps homogenised designs to fine-scale microchannel networks, maintaining continuous variations in channel properties and improving robustness while reducing computational expense compared to the conventional projection-based method. An idealised two-dimensional chip with heterogeneous heat generation is used to demonstrate the integrated design workflow. The homogenisation-based TO is performed on a coarse $50 \times 50 \mathrm{mesh}$, with the phasor-based dehomogenisation reconstructing fine-scale microchannel networks on a $3213 \times 3213$ mesh. The results show that the framework achieves a three orders-of-magnitude reduction in computational cost compared to hypothetical brute-force full-scale optimisation and a $\mathbf{3 5. 3} \%$ improvement in thermal performance over traditional pin-fin designs (the initial guess). Limitations of the current study, such as refining the homogenisation model and incorporating irregular meshes, point to promising directions for future investigations.