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Record 1,  Textual support,  English

Record number: 1, Textual support number: 1 CONT

In the homogeneous equilibrium model (HEM) one assumes that the velocity, temperature and pressure between the phases or components are equal.  1, record 1, English, - homogeneous%20equilibrium%20model

Record number: 1, Textual support number: 1 OBS

This assumption is based on the belief that differences in these three potential variables (and chemical potential if chemical reactions are considered) will promote momentum, energy, and mass transfer between the phases rapidly enough so that equilibrium is reached. For example, when one phase is finely dispersed in another phase generating large interfacial area, under certain circumstances this assumption can be made; e.g., bubbly flow of air in water or steam in water at high pressures. The resulting equations resemble those for a pseudo-fluid with mixture properties and an equation of state which links the phases to obtain these mixture thermodynamic properties. Whenever the HEM model is used it is advisable to check the validity of the equilibrium assumptions by using more accurate theoretical models for comparison. For example, rapid acceleration or pressure changes cannot be always accurately modelled with the HEM model; i.e., discharge of flashing vapor-liquid mixtures, or shock wave propagation through a multiphase medium. This is especially true when the pressure change is large when compared to the ambient pressure, or any of the driving potentials are large relative to their reference values.  1, record 1, English, - homogeneous%20equilibrium%20model

Record 1,  Textual support,  French

Record number: 1, Textual support number: 1 CONT

Les écoulements à direction privilégiée peuvent soit être considérés comme monodimensionnels, soit conduire à des équations simplifiées en ne considérant que les termes prédominants. Le modèle le plus simple revient à homogénéiser les deux phases en considérant un fluide dont les propriétés physiques sont déterminées par le taux de présence des deux phases. En écoulement à direction privilégiée (vertical ascendant), les deux phases étant en équilibre thermodynamique et mécanique, le modèle homogène à l'équilibre (HEM) se révèle satisfaisant et particulièrement utile. À partir de ce modèle, on peut introduire des effets de glissement ou de déséquilibre thermique (apparition de vapeur lorsque le fluide n'est pas encore à saturation).  1, record 1, French, - mod%C3%A8le%20homog%C3%A8ne%20%C3%A0%20l%27%C3%A9quilibre

Record 1,  Textual support,  Spanish