Performance of nano encapsulated phase change material slurry heat transfer in a microchannel heat sink with dual-circular synthetic jets

A B S T R A C T This study analyzes the hydrodynamic and heat transfer performance of the nano encapsulated phase change material (NEPCM) slurry in a microchannel heat sink (MCHS) equipped with two circular synthetic jets (SJs). It focuses on understanding the effects of major influencing parameters on energy efficiency, including the NEPCM concentration, frequency, amplitude, inlet velocity, latent heat storage, heat flux, inlet temperature, and phase actuation. The heat transfer coefficient (HTC) enhancement is maximized to 28.5% at the particle concentration of 0.2 and 180 degrees out-of-phase actuation. However, the figure of merit (FOM) decreases as the NEPCM concentration increases. The optimum thermal performance is obtained at the NEPCM concentration of 0.05 in the 180 degrees out-of-phase SJs. The convective heat transfer is remarkably improved using actuators with higher frequency and amplitude values. The thermal performance of 180 degrees out-of-phase actuation is better than in-phase jets. The FOM is significantly enhanced by increasing the inlet Reynolds number. The latent heat of fusion intensifies the convection and conduction rate by 17% and 31%, respectively, as it increases from 107.1 to 250 kJ/kg. When the inlet temperature values are set to accommodate the melting range of the NEPCM, the maximum Nusselt number is obtained at the temperature of 297.15 K. (c) 2021 Elsevier Ltd. All rights reserved.