Marienhagen, Philipp

In the project H2MIXPROP, highly accurate data for several thermophysical properties of gaseous mixtures containing molecular hydrogen are obtained by state-of-the-art theoretical approaches and experimental methods. Such data are required for many technical applications in the transition of the energy supply system to renewable energy sources, in which hydrogen is expected to play a prominent role. This contribution describes theoretical results for cross second virial coefficients of several binary mixtures, the development and validation of a path integral Monte Carlo code for the simulation of quantum gases, and the current status of the experimental tasks.

We provide third to eighth virial coefficients of oblate, hard ellipsoids of revolution and hard lenses in dependence on their aspect ratio ν. Employing an algorithm optimized for hard anisotropic shapes, highly accurate data are accessible with comparatively small numerical effort. For both geometries, reduced virial coefficients B[over ̃]_{i}(ν)=B_{i}(ν)/B_{2}^{i-1}(ν) are in first approximation proportional to the inverse excess contribution α^{-1} of their excluded volume. The latter quantity is directly accessible from second virial coefficients and analytically known for convex bodies.