Thermal performance of MgO-SWCNT/water hybrid nanofluids in a zigzag walled cavity with differently shaped obstacles

This study examined the influence of geometric parameters on free convective heat transfer in a zigzag-walled cavity filled with a hybrid nano-fluid composed of magnesium oxide (MgO) and single-walled carbon nanotubes (SWCNT) suspended in water. Utilizing validated multi-physics software grounded in the Galerkin finite element method (GFEM), we systematically analyzed how variations in Rayleigh number (Ra) from 10 4 to 10 6 , nanofluid volume fraction ([Formula: see text]) ranging from 0.01 to 0.04, and the number of wall undulations (from 1 to 8) affect thermal performance. The findings revealed that both the Rayleigh number and the number of wall undulations had a significant positive impact on the average Nusselt number (Nu), indicating enhanced heat transfer rates. Among the various obstacle shapes investigated, the diamond-shaped configuration emerged as the most effective in promoting thermal performance due to its ability to create favorable flow patterns. This research provides valuable insights for optimizing heat transfer processes in complex geometrical configurations employing hybrid nanofluids, contributing to advancements in thermal system design.