Numerical study of the effect of baffle geometry on heat transfer ‎and pressure drop in microchannels containing Newtonian and ‎non-Newtonian fluids

Farzadnia, Hamid-Reza; Bahrami, Hamid-Reza; Ghaedi, Mahziyar

doi:10.30511/jmms.2025.2074024.1024

Numerical study of the effect of baffle geometry on heat transfer ‎and pressure drop in microchannels containing Newtonian and ‎non-Newtonian fluids

Document Type : Original Article

Authors

Hamid-Reza Farzadnia ¹

Hamid-Reza Bahrami ¹

Mahziyar Ghaedi ²

¹ Qom University of Technology, Qom, Iran

² Iran University of Science and Technology, Thehran, Iran

10.30511/jmms.2025.2074024.1024

Abstract

In this study, the effects of different baffle geometries, including square, triangular, rectangular, and circular, on the flow and heat transfer in a microchannel are investigated. Numerical simulations are performed using ANSYS Fluent. Both Newtonian and non-Newtonian fluids (carboxymethyl cellulose) with concentrations of 1% and 2% are analyzed at a Reynolds number of 200. The results indicate that baffle geometry significantly influences flow separation, vortex formation, and heat transfer. The triangular baffle generates the strongest vortices and the highest Nusselt number, while rectangular and semicircular baffles show less pronounced effects. The square baffle produces stable vortices and achieves a favorable balance between heat transfer enhancement and pressure drop. Increasing the Reynolds number improves the Nusselt number and overall performance. For the 2% non-Newtonian fluid, the performance index exceeds unity for all geometries, indicating enhanced thermo-hydraulic efficiency. Overall, the triangular baffle achieves the highest heat transfer, whereas the square baffle provides the best overall performance.

Keywords

Newtonian fluids

non-Newtonian fluids

heat transfer

liquid coolant

sudden expansion