Numerical Investigation of Interrupted Microchannel Heat Sink with Multi-Step Rectangular Ribs in the Transverse Microchambers

This study numerically explores the performance of multi-step rectangular ribs and their base surfaces in microchannel heat sinks using the finite volume method in ANSYS Fluent. To reduce computational cost, a symmetry-based approach was employed on a representative section of the microchannel.Among the rib designs, double-step ribs demonstrated superior thermal performance, with a ۱۴% increase in the thermal enhancement factor. Key metrics included a ۲۷.۳% rise in the Nusselt number and a ۴۱% increase in friction factor. The initial friction increase stems from vortex formation by rib steps, though this effect diminishes at higher Reynolds numbers.Further analysis revealed that expanding the top step surface area in double-step ribs yields notable benefits. When A₂ was set to ۱.۵A, the thermal enhancement factor rose by ۲۵%, while the Nusselt number and friction factor increased by ۴۲% and ۵۱%, respectively.These optimized rib structures show strong potential for industries demanding high-efficiency thermal management. Applications include electronics cooling—improving heat dissipation in processors and circuit boards; electric and hybrid vehicle systems—enhancing battery regulation and longevity; and high-performance computing and data centers—reducing cooling costs and improving reliability. The ribs also offer advantages in aerospace, avionics, and precision medical devices such as laser systems.By integrating advanced rib geometries into microchannel heat sinks, engineers can significantly improve heat transfer and durability across a range of sectors

Keywords:

Heat Transfer , Microchannel Heat Sink , Multi-Step Rib , Numerical simulation