On the Modeling of Non-Classical Problems Involving Liquid Jets and Films and Related Heat Transfer Processes

Non-classical subjects relating to the dynamics of jet and film flow and related heat transfer processes are considered. These problems, which are relevant to several technological applications, cannot completely be addressed in the frame of the canonical Navier-Stokes equations. The first example deals with the formation of a film flow as a result of the hydraulic shock of a vertical jet impinging on a horizontal plane. The effective thickness of the film resulting from the hydraulic shock is much less than the value obtained using the conventional approach (relying on the assumption of smooth flow), while the corresponding speed is much higher. The next case is a jet penetrating into a pool of another liquid, which under certain conditions can form a jet head of a fungoid shape. When the jet penetrates the pool, it expands sharply, and this situation is another example of circumstances where classical models are flawed. Moreover, by virtue of the intense radiating heat transfer taking place at the front of the jet, a high-temperature jet can penetrate a pool of evaporating coolant, like a "jet in a bag of steam". These exotic problems are modeled and explained in the present article along with experimental data used for model validation. Several new hydrodynamic phenomena discovered over recent years are presented together with their practical applications, in particular, the modes of soliton-like and shock-wave decay of jets during vibration and electromagnetic resonant decomposition of the jet into droplets of a given size. These phenomena are relevant to the areas of granulation of metal melts, cooling of molten corium during postulated severe accidents in nuclear power plants and in other industrial and technological devices and processes.