Speaker
Albert Yuen
Description
Albert Yuen (1,2); John Barnard (3); Richard More (1)
(1) Lawrence Berkeley National Laboratory, Berkeley, California, 94720, USA
(2) University of California, Berkeley, California, 94720, USA
(3) Lawrence Livermore National Laboratory, Livermore, California, 94550, USA
As the simplest description of material that exhibits a liquid- vapor two-phase state, the Van der Waals' fluid model can be used to obtain qualitative (and sometimes quantitative) information about the fluid dynamics of material in the two-phase regime. We apply the general one-dimensional self-similar solution of a rarefaction wave in an initially semi-infinite liquid, uniform in temperature and density, to the specific case of a Van der Waals' fluid. Using dimensionless variables, we obtain a set of profiles for the fluid density, temperature and velocity, that describes the fluid for a wide range of space, time, initial conditions, and Van der Waals' parameters. These dimensionless results may be used to interpret experiments in which a material is rapidly isochorically heated before expanding. In particular, ``plateaus'' in temperature, density and velocity as a function of position are observed characterizing entrance into the two-phase regime. We observe that these “plateaus” - as well as the maximum fluid velocities, the densities and the temperatures of the liquid before entering the two-phase regime - depend exclusively on the initial entropy.
Based on this set of universal dimensionless curves and the observed “plateaus”, we propose a semi-analytical method to determine the Van Der Waals parameters, the initial temperature and pressure from a single density profile recorded during the expansion.
Primary author
Albert Yuen
