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 for micro-channels of circular cross-section, with a straight tape, and with 100 ≤ 𝑅𝑒 ≤ 350a twisted tape that induces swirl in the flow. Al2O3 nanofluid at nanoparticle volume fractions = 0, 1, 2 and 3% is used as the coolant. The microchannel heat sink with swirl flow and with 𝜙the 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.