Design and performance investigations of microchannels with multiple inlets and outlets based on multi-objective topology optimization

Microchannel heat sinks represent a viable and promising strategy to address thermal management challenges in high-performance chips, where the channel layout serves as a critical factor governing hydrothermal performance. Traditional channel layouts largely depend on existing experience, which is inefficient and often fails to obtain optimal configurations. In this study, a multi-objective topology optimization method is adopted to optimize the channel layout of microchannel heat sinks with five different inlet-outlet configurations. By introducing a weighted sum method with the weight coefficients, the heat transfer performance, temperature uniformity and flow resistance are comprehensively considered. The results reveal that the branch density and geometric complexity of microchannels increase significantly with the increase of Reynolds number (Re) and weight coefficient ( w ) for heat dissipation. As the number of inlets and outlets increases, the average temperature ( T _ave), temperature standard deviation ( T _SD) and pressure drop (Δ p ) are significantly reduced. Furthermore, the opposite-side inlet-outlet configurations can further reduce the temperature non-uniformity and pressure drop. Compared with traditional microchannels, topology-optimized microchannels exhibit superior hydrothermal performance (HTP) and achieve a more uniform temperature distribution. Specifically, the average temperature and temperature standard deviation of TO-FSF are reduced by 6.8 K and 34.7%, respectively. The numerical results of average temperature and pressure drop agree well with experimental measurements, with a maximum error of less than 5%.