A numerical study of nanofluid natural convection in a cubic enclosure with a circular and an ellipsoidal cylinder

The results show highest heat transfer enhancement in the conduction dominated flow regime, where the enhanced thermal properties of nanofluids play an important role. When convection is the dominant heat transfer mechanism, the using nanofluids yields a smaller increase in heat transfer efficiency. Comparison of 2D and 3D results reveals consistently lower heat transfer rates in the 3D case. As the enclosure is tilted against gravity, the flow symmetry around an elliptical cylinder is lost and the overall heat transfer increases.