Apple-like Shape of Freezing Paraffin Wax Droplets and Its Origin

Paraffin wax stores energy in the form of latent heat at a nearly constant temperature during melting and releases this solidification. This effect is used industrial storage. At same time, possible deformation even small volumes material as result phase change insufficiently studied. In paper, physical nature such deformation, probably for first studied on example droplet paraffin wax. An unusual shape melted placed relatively cold glass plate was observed laboratory experiments. As solidifies, its upper surface becomes flat, dimple formed center surface, making look like fruit (pumpkins are more commonly shaped this, but authors prefer apples). A series experiments, well numerical modeling droplet’s thermal state, taking into account formation mushy zone between liquidus solidus, made it to understand role gravity gradual increase viscosity density changing and, particular, clarify mechanism upper. It shown that solidus responsible formation.