Related Experiment Video
Updated: Mar 27, 2026

An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
Characterization of rarefaction waves in van der Waals fluids
1Department of Nuclear Engineering, University of California, Berkeley, California 94720, USA; and Department of Physics, University of California, Berkeley, California 94720, USA; and Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
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.
Related Concept Videos
The Van der Waals Equation
Van der Waals Equation
First, the attractive forces between molecules, which are stronger at higher densities and reduce the pressure, are considered by adding to the pressure a term equal to the square of the molar density multiplied by a positive coefficient a. Second, the volume...
Real Gases: Effects of Intermolecular Forces and Molecular Volume Deriving Van der Waals Equation
Van der Waals Interactions
The de Broglie Wavelength
Deviation from Ideal Behaviour

