10. Kinetic Molecular Effects with Spheroidal State

Cooling of a hot surface by dropwise jets is widely useful in various engineering problems: power systems, metallurgy, cryogenic systems, space, and fire-fighting engineering. Progress in this field is retarded by the lack of full comprehension of the entire realm of phenomena occurring for an incident flow of fluid jet to a surface. The principal question governing the entire process of jet cooling pertains to the study of the coupling of dynamic and thermal drops with the surface. The problem of coupling drops with a hard hot surface has a long history. In 1966, a fragment of a treatise by Leidenfrost (a German physician and theologist) of 1756 was published (Leidenfrost JG, De Aquae Communis Nonnullis Qualitatibus Tractatus. Duisburg, 1756) [1]. This insightful manuscript appeared before the energy conservation law was discovered and before the real nature of heat was unveiled, in particular, the concept “heat of evaporation” was not formulated. The principal result, which made Leidenfrost’s name immortal, was his discovery of a new physical fact: at a certain temperature, a metal surface ceases to be wettable by water (and other liquids).