Experimental investigation of bentonite–graphene oxide nanofluid in serpentine microchannel liquid cooling systems for GPUs

• Novel bentonite–graphene oxide nanofluid formulated for GPU cooling applications. • Experimental study on serpentine microchannel liquid cooling system. • Nanofluid exhibited enhanced heat transfer compared to water and conventional heat sink. • Improved GPU thermal management with reduced operating temperature range. • Demonstrates potential of clay–graphene hybrid nanofluids for advanced cooling systems. Autonomous vehicles require controllers capable of processing huge computations at high speed. Graphical Processing Units (GPUs) contain hundreds of cores that perform parallel tasks rapidly. Hence, the market for GPUs has started growing; however, GPUs suffer a fatal loss in the form of heat when processing huge data. There are many thermal management methods employed to maintain the core temperature, one of the most widely used is microchannel liquid cooling system. This study has developed a novel nanofluid coolant (NB6) which exhibits improved thermal conductivity, better thermal range and lower cost. The study compares the efficiency of NB6 with conventional thermal management methods for GPUs – Aluminium heat sink and water. Additionally, a copper microchannel was developed with 14 square shaped serpentine channels, each measuring 0.5 mm in length. The analysis was for Nvidia Jetson nano development board under 10 W maximum power, with the coolant velocity ranging from 1.83 m/s to 2.25 m/s through the serpentine channel of total flow length of 521 mm and the test ran for 1121 seconds. The results revealed that NB6 achieved the lowest peak temperature of 88 °C, followed by water with 94 °C and heat sink with 101 °C. Comparing the ΔT - thermal range of GPU during the experiment; with heat sink ΔT was 58 °C, with water ΔT was 49 °C and NB6 displayed lowest ΔT of 41.5 °C. The analysis concludes by highlighting the superior efficiency of NB6 compared to conventional thermal management solutions currently used in the automotive industry.