Maria Stella Mongiovi†, Lidia Saluto‡
Abstract: In this paper, we consider an extension of the two-fluid model for superfluid helium. Over the years, two kinds of models have been pro- posed to describe the observations on helium II: the two-fluid model, in which the specific entropy of the superfluid is assumed to be zero, and the extended one-fluid model, derived from extended thermodynamics. Since the statement that the entropy of the superfluid fraction vanishes has not been demonstrated theoretically, in this paper we generalize the standard (Landau and Tisza) two-fluid model allowing that a small amount of entropy is carried by the superfluid component.
Keywords: superfluid helium, one-fluid model, two-fluid model.
MSC: 82D50.
DOI 10.56082/annalsarscimath.2025.3.445
† mariastella.mongiovi@gmail.com, Universita degli Studi di Palermo, Viale delle Scienze, 90128 Palermo, Italy
‡lidia.saluto@unipa.it, Universita` degli Studi di Palermo, Viale delle Scienze, 90128, Palermo, Italy
PUBLISHED in Annals Academy of Romanian Scientists Series on Mathematics and Its Application, Volume 17 no 3, 2025
