Investigation on the temperature distribution in the two-phase spider netted microchannel network heat sink with non-uniform heat flux

The considerable increase of the heat flux and chips density on the phased array antenna has brought great challenges to the thermal management. The objective of the work is to explore an effective scheme to achieve ideal uniform temperature distribution and lower maximum temperature with the condition of non-uniform heat flux. Taking into account of the high efficiency of microchannel heat sink and the promising performance of the two-phase flow boiling heat transfer due to its merit in keeping uniform surface temperature, a novel two-phase spider netted microchannel network heat sink is proposed in this paper. Firstly, a three-dimensional fluid-solid-thermal conjugate model is developed to investigate the flow boiling heat transfer performance of the spider-netted microchannel network numerically. During the numerical calculation, a multi-scale meshing generation method is proposed to reduce modeling difficulties on the premise of proper mesh quality. Then, the flow boiling heat transfer experiment is conducted to verify the reasonable of the model and the simulation results. Finally, the flow boiling heat transfer performance in the spider netted microchannel network is compared to the typical straight microchannel network. Results show that the proposed structure yields better flow boiling heat transfer performance with lower thermal resistance and more satisfactory temperature uniformity mainly due to its uniform flow distribution and enhanced vapor movement. It is also found that the temperature uniformity has reached 1.58 °C at heat flux of 100 W/cm2, but it decreases with the increase of heat flux. This situation cannot be effectively solved by means of increasing inlet flow rate. Thus the structure optimization is conducted to enhance the flow boiling heat transfer performance further, and the optimal structure can meet requirements of temperature uniformity within 2 °C at higher heat flux of 150 W/cm2.