Fellowship for Nathaniel Barlow: Asymptotically Guided Calculations of Thermophysical Properties

This research focuses on the development, implementation, and application of new computational methods for characterizing the behavior of fluids from molecular models. The analytical formulation is based on the virial equation of state (VEOS). To guide the calculation of virial coefficients, asymptotic expansion methods are applied in two ways: (1) to more accurately capture the behavior near the vapor-liquid critical point, and (2) to characterize the temperature dependence from sub- to super-critical conditions. The actual calculations are implemented on an HPC cluster system using newly acquired Netezza Data Intensive Super Computer (DISC) hardware, in an effort to keep the data close to the processors. This gives us the opportunity to develop novel data-intensive algorithms that work in unison with the DISC system The VEOS and related methods are appealing routes to describing fluid-phase behavior, because they are based rigorously on molecular considerations. Specifically, the VEOS expresses the pressure as a power series in density. One of the limitations of this treatment is encountered in applications near the vapor-liquid critical point, where the true behavior is known to be non-analytic. Crossover methods and asymptotic analysis can remedy this problem, while also suggesting novel routes to perform the calculations. A side effect of this development is the huge proliferation of so-called cluster integrals that are required for calculation, making this a problem that is ideally suited for computational research. The computations are structured such that independent calculations can be combined to yield a precise result for a given cluster integral. Although computationally expensive, the approach is perfectly parallelizable, and thus the calculations are well conditioned for new multi-core architectures and distributed-processor paradigms.