Nayema Islam Nima, Shahina Akter , Jahangir Alam

Abstract: This study explores the influence of thermal dispersion on mixed convection flow of a hybrid nanofluid past a horizontal cone. The working fluid is ethylene glycol containing cylindrical alumina (Al₂O₃) and silica (SiO₂) nanoparticles in equal volume fractions. Compared with a single alumina-based nanofluid, the hybrid suspension exhibits significantly improved thermal transport capability. To analyze the problem, the governing nonlinear partial differential equations are reduced to ordinary differential equations using similarity transformations, and the resulting system is solved numerically with the Bvp4c method. The investigation shows that suction strongly enhances the heat transfer rate by reducing the thickness of the thermal boundary layer, while injection diminishes it, particularly under forced convection conditions. Thermal dispersion is found to decrease heat transfer efficiency by weakening the near-wall temperature gradient, with its impact being more pronounced in forced and mixed convection regions. In contrast, a higher Biot number consistently increases heat transfer, with stronger effects observed as the flow approaches free convection dominance. Overall, the results demonstrate that hybrid nanofluids, when coupled with optimized boundary conditions, can deliver substantial improvements in convective heat transfer performance. These findings underscore the potential application of such fluids in advanced cooling systems, heat exchangers, and energy-related technologies where efficient thermal regulation is critical.

Keywords: dispersion, suction/injection, hybrid nanofluid, ethylene glycol, forced convection.

Date Published: November 26, 2025
DOI: 10.11159/jffhmt.2025.035

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