Simulation and optimization of thermal performance in diverging/converging manifold microchannel heat sink

Increasing complexity of electronic devices and chips places increasingly stringent requirements on heat sinks. A novel manifold microchannel heat sink with diverging/converging channels is proposed to improve heat transfer performance. The flow and heat transfer characteristics under single-phase are investigated numerically. The effects of two key parameters, manifold inlet to outlet ratio α and channel inlet to outlet ratio β, and their combinations on the thermal-hydraulic performance are explored. The results show that, in the single parameter optimization, a moderately diverging manifold layout and a converging channel layout each have the best enhancement effect on heat transfer for given pumping power, reducing the thermal resistance by 11.1% and 13.5% than homogeneous structure, respectively. When both parameters are set as optimization variables, the parameter combinations with enhanced performance are distributed in a sloping downward band in the parameter diagram. The configuration with α = 1/9 and β = 9 has the best reinforcement effect, reducing the thermal resistance by 19.18% for a given pumping power of 5×10⁻⁴ W. In addition, the heat transfer characteristics of the optimum and original configurations under non-uniform heating flux are also investigated for application, with the optimum configuration showing better performance at both temperature level and temperature uniformity.