Comparative study for convective heat transfer of counter-flow wavy double-layer microchannel heat sinks in staggered arrangement

This study proposes a modification of double-layer Microchannel Heat Sinks (DMHSs) into wavy configuration with swap of upper and lower layer design. The design can effectively improve the comparatively low cooling effectiveness at the upper layer, yet the swap of flow can promote re-developing of flow field and heat transfer accordingly. Both parallel and counter flow arrangements of the proposed configurations are examined in details. It is found that the staggered wavy DMHSs with opposite amplitude shows superior heat transfer enhancement. Regardless of the types of heat sink being investigated, the maximum temperature for all parallel flow arrangement always occurs at the exit while the maximum temperature for counter flow is in the interior of heat sink but is close to the exit. Interestingly, the swap design of counter flow arrangement (parallel channel or wavy) shows two maximum temperatures in the first and second half of the heat sink. Basically, the counter flow of straight staggered DMHS has the best overall thermal performance among the counter flows of straight parallel DMHS, synclastic wavy staggered DMHS and opposite wavy staggered DMHS. This is because the wavy staggered DMHS incur more pressure drop and pumping power accordingly.