Experimental examination of the cooling performance of a cylindrical microchannel heat sink with straight and sinusoidal fins and alumina nanofluid coolant

Miniaturization of the electronic devices and dissipation of the heat generated during the operations within such equipment are of the most important issues in the design of these components. In the current experimental study, it is shown that deploying a cylindrical microchannel heat sink (CMHS) results in a superior efficiency for cooling the equipment when sinusoidally wavy fins are applied with an innovative structure in its geometry rather than the straight ones. The heat sinks considered include 80 straight/wavy microchannels with hydraulic radius of 589 mu m and fins of 600 mu m in both width and height located on a cylinder. In order to further enhance the heat transfer, alumina nanoparticles were used at three different concentrations, namely 0, 0.1, and 0.3 mass%. In the experiments performed using the base fluid, it is demonstrated that with increase in the Reynolds number in the range of 200-1000, the Nusselt number of the sinusoidal microchannels rises by 6-40% in comparison with that of straight microchannels. In addition, the use of the nanofluid instead of the base fluid further improves the heat transfer coefficient in the both cylindrical microchannels with straight and sinusoidal fins, such that an increase in the concentration of the nanofluid enhances the Nusselt number accordingly. Comparison between the thermal performance of the sinusoidal wavy fins to that of the straight ones in the same conditions (the size and geometry of the heat sink) illustrates that greatly improved thermal performance is achieved utilizing the sinusoidal fins. Also, the application of alumina nanofluids improves the thermo-hydraulic performance index (THPI) of the straight and the wavy CMHSs. The performance index range of 1.05-1.07 and 0.82-1.07 was obtained, respectively, for the 0.3 mass% nanofluid flow in the straight and wavy CMHSs.

Automated summary

In the current experimental study, it is shown that deploying a cylindrical microchannel heat sink with sinusoidally wavy fins results in superior efficiency for cooling the equipment compared to straight fins. The use of alumina nanoparticles in nanofluids further enhances the heat transfer coefficient in both cylindrical microchannels with straight and sinusoidal fins, with increasing nanofluid concentration corresponding to an increase in Nusselt number.