Enhancing Heat Dissipation in Microchannel Heat Sinks: A Comprehensive Study on Al₂O₃ Nanoparticle Concentration and Flow Rate Dependencies

Abstract

This study aimed to investigate the influence of Al2O3 nanoparticle concentration and flow rate on the convective heat transfer coefficient in a heat sink. A testing apparatus was constructed to examine a microchannel heat sink coupled with an Al2O3 nanoparticle fluid. Temperature sensors were strategically placed at the microchannel heat sink’s entrance (T-in) and exit (T-out). Furthermore, a heating element (T-heater) was utilized to monitor the temperature of the nanoparticle fluid. This experimental setup allowed for precise temperature measurements in the system. Aluminum oxide (Al2O3) nanoparticles were thoroughly dispersed in water for 15 min using a magnetic stirrer, resulting in a uniform mixture with concentrations ranging from 0.2% to 1%. The experiments involved altering the flow rates within the range of 0.2 to 1.4 L per minute, enabling the monitoring of temperature changes (T). The heat transfer coefficient positively correlated with escalating concentrations of Al2O3 particles. Incorporating nanoparticles up to a concentration of 1% significantly enhanced the heat transfer coefficient by 17.29%. Additionally, a direct relationship was observed between the heat transfer coefficient and the increase in the flow rate of the Al2O3/water nanofluid. Specifically, when the flow rate was increased from 0.2 to 1.4 lpm, a significant enhancement in the heat transfer coefficient of 29.95% was achieved.

Keywords

• Al₂O₃
• nanofluid
• nanoparticle concentration
• flow rate
• heat sink
• microchannel