Water Cavitation From Ambient to High Temperatures

Abstract Cavitation is a ubiquitous phenomenon which is in principle well understood. However predicting its occurrence has proved a formidable task, particularly for the most common case of water, even for the simplest, homogeneous, conditions. Experimentally, the main difficulty is related to the unavoidable contamination of the sample, whose purity is difficult to control. Nevertheless there is nowadays substantial consensus on the remarkable tensile strength of water, on the order of-120 MPa at ambient conditions. Many factors concur in making the theoretical predictions even more difficult. The reference theory is the classical nucleation theory which leads, though the adaptation of Kramers’s theory of chemical reactions, to a qualitatively correct description. As recently pointed out, accounting for the surface tension dependence on the interface curvature may lead to a much better correspondence with experiments. Nevertheless the prediction still depends on elaborate fitting procedures based on data from model-fluid molecular dynamics simulations. Here a self-contained model is discussed which is shown able to accurately reproduce cavitation data for water over the most extended range of temperatures for which accurate experiments are available. The computations are based on a diffuse interface model which, as only inputs, requires a reliable equation of state for bulk free energy and interfacial tension of the water-vapor system combined with rare event techniques.