Heat Transfer Enhancement in a Microchannel Heat Sink: Nanofluids and/or Micro Pin Fins

Abstract

Here, we show that overall thermal conductance in a rectangular microchannel heat sink can be maximized with the combination of nanofluids and micro pin fins. We uncover the effect of micro pin fins and nanofluids both separately and simultaneously in order to uncover their effect on the thermal conductance (i.e., thermal resistance). Both nanofluids and micro pin fins decrease the overall thermal resistance due to increase in the average thermal conductivity of the flow system. In addition, they increase the heat transfer surface area of the solid interacting with the fluid. However, the pumping power (pressure drop) increases in both methods due to the increase in the resistances to the fluid flow. The results document what should be the nanoparticle volume fraction mixed into the base fluid and the micro pin fin volume in order to minimize thermal resistance. If the thermal conductivity of the nanoparticles and micro pin fins are the same, the thermal conductance becomes the maximum with 4% and 0.14% volume fractions for the nanofluid and micro pin fins, respectively. This result shows that inserting micro pin fins and using nanofluids with a given volume fraction ratio maximize the overall thermal conductance.

Additional information

Notes on contributors

Turgay Coşkun

Turgay Coskun is currently Research Assistant and Ph.D. student at Izmir Institute of Technology, Izmir, Turkey. He received his B.S. degree in Mechanical Engineering in 2013 and his M.Sc. degree in Energy Engineering in 2016 from the same university. His research interests include heat transfer in microchannels and nanofluids.

Erdal Çetkin

Erdal Cetkin is a Professor of Faculty of Engineering at Izmir Institute of Technology, Izmir, Turkey. He received his Ph.D. in Thermofluidics in 2013 from Duke University, Durham, N.C., USA. He is currently working on heat transfer enhancement methods, heat transfer with phase change materials, mass transfer in micromixers and manifold design optimization.