Modeling gaseous and vaporous cavitation in liquid flows within the context of the thermodynamics of irreversible processes

Abstract

This paper deals with the modeling of gaseous and vaporous cavitation in homogeneous and isothermal flows of compressible Newtonian liquids. The constitutive equations are derived within the framework of the thermodynamics of irreversible processes. The rate mass transfer related to the cavitation phenomena are consistently described as irreversible processes, being each of these mechanisms associated with a specific rate of energy dissipation. By means of a simple numerical simulation, which describes an expansion motion of water at room temperature confined in a piston–cylinder system, the influence of each type of cavitation on the mechanical response of the fluid is investigated, when they act isolatedly and simultaneously. The obtained results show that quite distinct physical behaviors are observed. The vaporous cavitation significantly inhibits the mass transfer process associated with the gaseous cavitation, but the reciprocal is not true.