Natural convection in a melting material (hexadecane) is studied experimentally using Magnetic Resonance Imaging. This imaging technique allows to discriminate solid and liquid phases measure velocity vectors the volume sample, even through/in opaque phases. Within our experimental conditions, occurs above Ra≈1430. The thermo-convective flow affects interface leading higher height uprising lowe...

Natural convection heat transfer is present in the most diverse applications of Thermal Engineering, such as electronic equipment, transmission lines, cooling coils, biological systems, etc. The correct physical-mathematical modeling this phenomenon crucial applied understanding its fundamentals and design thermal systems related technologies. Dimensionless analyses can be study flows to reduce...

Using boundary-layer theory, natural convection heat transfer formulas which are accurate over a wide range of Rayleigh numbers ($Ra$) were developed in the 1970s and 1980s for vertical downward-facing plates. A comprehensive formula upward-facing plates remained unsolved because they do not form conventional boundary-layers. From thermodynamic constraints on heat-engine efficiency, novel appro...