Modares Mechanical Engineering

Modares Mechanical Engineering

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

Document Type : Original Research

Authors
Hossein Karbasian 1
Abas ramiar 2
Amirhosein Ghasemi 3
1 BSc student of Mechanical Engineering, Babol Noshirvani University of Technology, Babol,Iran
2 Associated professor, Babol Noshirvani University of Technology, Babol, Iran
3 Assistant professor, Babol Noshirvani University of Technology, Babol, Iran
10.48311/mme.2025.116431.0
Abstract
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 14% increase in the thermal enhancement factor. Key metrics included a 27.3% rise in the Nusselt number and a 41% 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 1.5A, the thermal enhancement factor rose by 25%, while the Nusselt number and friction factor increased by 42% and 51%, 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
Subjects
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Modares Mechanical Engineering
Volume 25, Issue 11
November 2025
Pages 695-701