Experimental study on the hydrothermal performance of nanofluids-cooled heat sinks with diamond shape micro pin-fin structures

Modern electronic devices with small heat transfer areas have very high heat flux. As a result, high temperatures are attained by these devices. Proper heat dissipation must be done to avoid damaging them. Thus, thermal and hydraulic performance of novel heat sinks with two different diamond-shaped micro-pin-fin (MPF) arrangements, inline and staggered, are experimentally examined. This has not yet been reported in the research literature. Heat sinks (HSS) with dimensions of about 30 mm x 33 mm are fabricated from copper. MPFS are designed with a diamond shape and arranged in inline (DPFHS-I) and staggered (DPFHS-S) layouts. Hydraulic diameters of each flow channel are kept constant at 1.0 mm for DPFHS-I and DPFHS-S. At first, DI water flows through the test section under laminar flow. Reynolds numbers (Re) based on the hydraulic diameter ranged from 100 to 600. Then, SiO2–water nanofluids with various particle volume fractions (ϕ) are tested to determine their potential for heat removal and apparent pressure drop (ΔP) across the heat sink, compared to water. Wall heat fluxes ranging between 10 and 52 kW/m2 are applied. The effects of pin-fin layout, Re, and ϕ on the cooling performance, performance index (PI), and ΔP are examined. Experimental results illustrate that the thermal performance is augmented with increasing Re and ϕ. The DPFHS-S had around 3–10 % higher thermal performance than the DPFHS-I. Experimental data indicated that using nanofluid coolants had a small effect on the ΔP and pumping power. Finally, new correlations for the Nusselt number and ΔP are proposed that are simple and can be used in practical applications. Most of the predicted data lies within ±10 % of the experimental data. © 2024