Heat Sink Cooling by Nanofluids: TiO₂, SiO₂, and Fe₃O₄

Heat Sink Cooling Performance Using Water and Nanofluids (TiO₂, SiO₂, Fe₃O₄) in ANSYS Fluent

Description

This project presents a numerical analysis of heat transfer and fluid flow through a heat sink using ANSYS Fluent, investigating how different working fluids affect overall cooling performance. Four cases were examined: water alone as a single-phase baseline (Case 1), followed by three nanofluid cases using water combined with TiO₂ (Case 2), SiO₂ (Case 3), and Fe₃O₄ (Case 4) nanoparticles. For the nanofluid cases, the Mixture multiphase model was applied, with water defined as the primary phase and each respective nanoparticle type as the secondary phase.

The computational domain represents a heat sink structure comprising one fluid zone and two solid zones — the base plate and the fins. The geometry was built in Design Modeler to capture both fluid and solid regions in sufficient detail to resolve the heat transfer process accurately, and the domain was meshed in ANSYS Meshing, producing a high-quality mesh of approximately 1.6 million elements that captures fine geometric detail while keeping computational cost reasonable.

Methodology

All four cases were solved under steady-state conditions using a pressure-based solver, with the SIMPLE algorithm handling pressure-velocity coupling and discretization schemes chosen carefully to minimize numerical diffusion. Case 1 used a single-phase flow model, while Cases 2 through 4 applied the Mixture multiphase model to capture the interaction between the water carrier fluid and each nanoparticle type.

Boundary conditions were consistent across all cases: a velocity inlet at 1.96 m/s, a pressure outlet, and no-slip wall conditions with appropriate heat flux or temperature assignments throughout the domain.

Conclusion

The resulting temperature and velocity contours reveal clear differences in cooling behavior across the four cases. Case 1 (pure water) established the baseline thermal and flow behavior. Case 2 (water + TiO₂) showed improved heat dissipation relative to pure water, while Case 3 (water + SiO₂) achieved even better cooling performance thanks to SiO₂'s enhanced thermal conductivity. Case 4 (water + Fe₃O₄) showed the most substantial improvement, with considerably lower temperatures near both the fins and the base plate.

These trends are reflected clearly in the summarized zone temperatures:

Across the fin and base plate zones — the regions most critical to effective heat sink performance — the addition of nanoparticles consistently reduced temperatures compared to water alone, with the heat distribution also becoming more uniform. Among the three nanofluids tested, Fe₃O₄-water delivered the strongest cooling performance, followed by SiO₂-water and then TiO₂-water — confirming the potential of magnetite-based nanofluids as particularly effective advanced coolants for electronics and industrial thermal management applications.