Heat transfer enhancement and optimization for novel secondary connected wavy fractal MCHS

For high-energy and electronic devices to operate steadily, microchannel heat sinks (MCHS) must dissipate heat quickly. This feature improves device reliability, which is essential for demanding applications in micro-electro-mechanical systems. This work explored the thermal and hydraulic characteristics of secondary connected fractal heat sink (SC-FHS) and wavy fractal heat sink (SC-WFHS) devices manufactured by metallic 3D printing using both numerical and experimental approaches. MCHS inserts are fabricated by laser powder bed fusion technology from AlSi10Mg metal powder. Casing for the inserts is printed by stereolithography technique from Model V3 photosensitive resin. Only single-phase flow is considered with water as coolant. The range of volumetric flow rate (˙v) is from 100 to 300 ml/min. Further, numerical parametric study is conducted by varying wavy amplitude (A) of SC-WFHS device. The thermal performance of SC-WFHS (A=0.5 mm) device is found superior compared to SC-FHS (A=0 mm). Maximum enhancement of 53% is found in average Nusselt number (Nu) of SC-WFHS (A=0.5 mm) device at ˙v=300 ml/min. compared to SC-FHS (A=0 mm). Better flow circulation with increased velocity in secondary connected channel of SC-WFHS improves the temperature distribution by mitigating the hotspots compared to SC-FHS device. SC-WFHS (A=0.5 mm) device operating at ˙v=300 ml/min. is found optimal for thermo-hydraulic performance according to VIKOR optimization method.