Convective heat transfer and mixing enhancement in a microchannel with a pillar

An experimental study of heat transfer in microchannel with pillar/pillars was conducted with air. Area-averaged temperature was measured by a 1 × 1 mm2 resistance temperature detector (RTD), and data were collected over the range 100 ⩽ Re ⩽ 5600. The microchannel with a pillar had a heat transfer coefficient that was twice that of the channel without a pillar. Among the three geometric shapes of pillar studied, triangular pillar performed the best with 17.7 ⩽ (Nu) ⩽ 88.9. Micro particle image velocimetry (μPIV) was used to measure the velocity field in the mircochannel and turbulent kinetic energy (TKE) calculation provided a measure of flow mixing. It was shown that TKE is closely related to the thermal performance and can be used to predict the Nusselt number.