Performance of nanofluid flow in corrugated minichannels heat sink (CMCHS)

Highlights: • Cooling performance of MCHSs is studied using corrugated channels and nanofluid. • Effects of wave-length/wave amplitude and nanoparticles concentration are studied. • Presence of Al₂O₃ nanoparticles in base fluid improves the performance of MCHSs. • Highest PEC of 3.5 is obtained for the compound technique at the highest flow rate. • Universal correlations are proposed for Nusselt number, friction factor, and PEC. - Abstract: Firstly, a brief review of previous works on the nanofluid flow in the minichannels heat sink (MCHS) is carried out. Then, the corrugated minichannels heat sink (CMCHS) and Al₂O₃/water nanofluid are proposed aiming more compact equipment and efficient cooling. The effects of geometrical parameters, nanoparticles weight fraction, and flow rate are investigated. Experimental tests are performed in a precise close loop setup with the ability to produce a constant heat flux. The results show that the CMCHSs can improve the heat transfer performance, albeit with a penalty in the pressure drop compared with the straight MCHS. It is also found that both the heat transfer enhancement and the pressure drop penalty augment, as the wave-length decreases and wave-amplitude increases. However, in the studied ranges, the effect of wave-amplitude is more than that of wave-length. The base temperature and convective thermal resistance are found to drop by decreasing the wave-length and by increasing the wave-amplitude. At a heater power of 50 W, the lowest base temperature of 30.5 °C is achieved by using a CMCHS of 20 mm wave-length and 2 mm wave-amplitude. It is detected that the thermal–hydraulic performance of CMCHSs improves, as the weight fraction of nanoparticles increases. Noticeable average performance factor of 2.68 is obtained for the simultaneous utilization of corrugated minichannels and Al₂O₃/water nanofluid inside the MCHS.