A Novel Liquid Cooled Heat Sink with Adjacent Micro Synthetic Jets for Thermal Management in Microelectronic Devices

This paper investigates the use of flow vectoring phenomena in adjacent synthetic jets for cooling hot spots in a microchannel. By applying an appropriate phase difference, fluid flow is induced within the microchannel using adjacent synthetic jets. The performance of this configuration is evaluated under conditions representative of cooling electronic packages using pure water and water- Al₂ O₃ nanofluids with varying concentrations and particle diameters while maintaining constant jet operating conditions. The addition of nanoparticles alters the fluid properties, resulting in two competing effects: weakened jet performance due to increased viscosity and enhanced heat transfer through improved thermal conductivity. Both effects are analysed, and the best performance is observed with water-based nanofluids, showing a 4.5% enhancement in heat transfer compared to pure water under the same operating conditions. This indicates that although the same input power is applied to both water and nanofluids, the latter exhibits a lower Re_j due to changes in fluid properties but demonstrates better performance in cooling the hot spot. When the Re_j is kept constant, a 21% enhancement in heat transfer is achieved for water- Al₂O₃ at φ= 5% and d_p=30 nm compared to pure water.