Multi-objective optimization of wavy microchannel heat sinks with symmetric configurations generated by interpolation curves

Microchannel heat sinks (MCHS) with symmetric configurations enhance fluid flow disturbances through expansion-contraction sections, improving heat transfer performance. This paper presents an optimal design for symmetrically curved MCHS generated by using interpolation curves. The multi-objective genetic algorithm based on decomposition (MOEA/D) is used to achieve the optimization of three design variables, and pumping power and thermal resistance are considered as the objective functions. Partial correlation analysis reveals that the design variables W1 and W3 describing the width of microchannels have the greatest influence on the two objective functions with different trends. The technique for order of preference by similarity to ideal solution (TOPSIS) is used to select the optimal compromise solution from the Pareto-optimal solutions. The channel first widens and then narrows in each unit of the TOPSIS solution and the solution with the minimum consumption of pumping power and maximum thermal resistance, which is opposite to the solution with the maximum consumption of pumping power and minimum thermal resistance. The widening position in TOPSIS solution is closer to the downstream and this configuration reduces the pressure drop while maintaining the fluid disturbance effect of the expansion-contraction sections. Compared to the straight channel, the optimal compromise solution selected by TOPSIS strategy reduces the consumption of pumping power by 10.0 % and the thermal resistance by 47.0 % concurrently. Therefore, the optimal MCHS with the TOPSIS solution and the optimization approach are highly applicable in practice.