Eulerian multiphase technique for detailed investigation on hydro-thermal enhancement in a cooling microchannel using pulsating alumina nanofluid: A numerical simulation

Abstract

This study explored the impact of pulsation on the hydro-thermal behavior of an interrupted microchannel heat sink. A homogeneous blend of Al2O3-water was employed as the coolant. The investigation considers the influence of varying amplitude, pulsation frequency and Reynolds number. Findings indicate that using pulsating flow instead of steady flow substantially improved the thermal efficiency of the microchannel. The pulsating flow was observed to improve the Nusselt number by 17.43 %, 33.38 %, 50.66 %, 68.39 %, and 86.12 % at 5, 10, 15, 20, and 25 Hz, respectively compared to a steady flow. However, with heat transfer enhancement, there is an accompanying pressure drop caused by pulsating flow. Pressure drops increased with the pulsation frequency and reached a maximum value of 0.2695 MPa at f = 25 Hz and A = 0.8. Nevertheless, the performance evaluation criteria showed that although pulsating flow increases pressure drop, it offers significantly better overall thermal and hydraulic performance than steady flow. The PEC improved by 90.47 % at Re = 100, f = 25 Hz, and A = 0.2. The results demonstrate a conceivable technique to use pulsating flow to improve heat transfer performance in systems with high power density in confined spaces.

Keywords

• Cooling microchannel
• Nanofluids
• Pulsating flow
• Thermohydraulic
• PEC