IMPACT OF SILVER NANOPARTICLE (AgNP) COATING THICKNESS ON HEAT DISSIPATION, AIRFLOW DYNAMICS, AND THERMAL RESPONSE OF COATED HEAT SINK

The nanocoating technique allows a small amount of precious metal to be coated onto a heat sink to participate in thermal management. This study investigates the effect of silver nanoparticle coating thicknesses on heat dissipation, airflow dynamics, and the thermal response of the coated heat sink under natural convection. In this paper, the heat sink coated with silver nanoparticle coatings of different thicknesses (10-500 μm) is simulated using the ANSYS Fluent software. Validation of the simulation results is performed using previous experimental findings, which record a percentage error below 4%. As the coating thickness increases, the steady-state temperature and thermal resistance rise. The 10-μm-coated heat sink performs the best with the highest average overall heat transfer coefficient of 6.09340 W m<sup>–2</sup> K<sup>–1</sup> and average convective heat transfer coefficient of 5.90574 W m<sup>–2</sup> K<sup>–1</sup>. The uncoated heat sink records a thermal resistance of 5.3174 K W<sup>–1</sup>, which lies between those of the 100-μm- and 150-μm-coated heat sinks. This shows that a silver nanoparticle coating can enhance the cooling performance of the bare heat sink, but further increases in coating thickness lead to poorer thermal performance. Focusing on the heating process, among the five variations compared, thicker coatings require a longer thermal response time than the thinner ones. This study contributes to the understanding that AgNP coatings improve heat dissipation, and their effectiveness diminishes with increased thickness, providing valuable insights for optimizing nanocoating applications in thermal management systems.