Thermo-hydraulic performance of a circular microchannel heat sink using swirl flow and nanofluid

Increasing the power and reliability of microelectronic components requires heat sinks with greater heat transport performance. This study investigates the hydraulic and heat transport performance of a silicon heat sink under a constant heat flux of 100 W/cm² with liquid coolant running through parallel microchannels. The coupled heat transfer through the silicon walls and the coolant, modelled as a single-phase fluid, is examined over the Reynolds number range 100 to 350 for micro-channels of circular cross-section, with a straight tape, and with a twisted tape that induces swirl in the flow. Al₂O₃ nanofluid at nanoparticle volume fractions phi = 0, 1, 2 and 3% is used as the coolant. The microchannel heat sink with swirl flow and with the highest nanoparticle volume fraction concentration provides the lowest thermal resistance and contact temperature. Whilst it has a higher flow resistance than the micro-channel with no tape cooled by pure water, it has a positive trade-off between the gains in cooling performance and in flow resistance. This makes these configurations attractive for designing more performing heat sinks for temperature limited or temperature sensitive micro-electronics.