Pressure Impulse during Explosive Boiling on the Surface of a High Temperature Melt in Water—Discussion of the Calculation Model

This study explores the mechanism behind the generation of pressure pulses on the outer surface of a molten metal droplet when immersed in water. The absence of any external trigger is assumed, and the droplet is surrounded by a vapor layer with surface hydrodynamic waves at the vapor-liquid interface. The study examines the heating conditions of a cylindrical column of water used to model a volume of cold liquid interacting with a hot metal surface, which explosively boils upon direct contact. Within the framework of classical homogeneous nucleation theory, the relationship between pressure pulse magnitude and rise time and the size of the contact area and surface temperature of the droplet is established. A criterion for determining the magnitude of the pressure pulse is derived, showing that significant pressure pulses occur within a narrow range of values for this criterion. Experimental investigations have been conducted to measure the key parameters—such as the duration and area of contact and pressure amplitude buildup—when room-temperature water comes into contact with a hot steel surface. The experimental results are compared with the theoretical predictions. Incorporating Skripov’s theory of explosive boiling into the model helps explain the relationship between the pressure pulse and contact area, only when the droplet surface temperature is near or exceeds the temperature of the maximum possible water superheating.