Characterization of rarefaction waves in van der Waals fluids

Abstract

We calculate the isentropic evolution of an instantaneously heated foil, assuming a van der Waals equation of state with the Maxwell construction. The analysis by Yuen and Barnard [Phys. Rev. E 92, 033019 (2015)] is extended for the particular case of three degrees of freedom. We assume heating to temperatures in the vicinity of the critical point. The self-similar profiles of the rarefaction waves describing the evolution of the foil display plateaus in density and temperature due to a phase transition from the single-phase to the two-phase regime. The hydrodynamic equations are expressed in a dimensionless form and the solutions form a set of universal curves, depending on a single parameter: the dimensionless initial entropy. We characterize the rarefaction waves by calculating how the plateau length, density, pressure, temperature, velocity, internal energy, and sound speed vary with dimensionless initial entropy.

Arguing on Entropic and Enthalpic First-Order Phase Transitions in Strongly Interacting Matter

“…A prominent example for type II is the van der Waals equation of state, cf. [51] and figure 1 in [52]. We emphasize the local character of our consideration, that is the restriction to the vicinity of a T -µ point on the presumed phase boundary.…”