Effects of Equations of State Selection in Numerical Simulations of Supercritical Carbon Dioxide
ORAL
Abstract
Supercritical carbon dioxide (sCO$_{\mathrm{2}})$ is employed in a growing range of applications including novel material synthesis and advanced energy systems. However, a lack of understanding of how the complex behavior of sCO$_{\mathrm{2\thinspace }}$near the critical point 304.25 K and 7.39 MPa affects the flow field, accompanied by numeric challenges of simulating under these conditions, limits the use of simulation as a predictive tool in these systems. Initial simulations using the high-fidelity Span-Wagner equation of state at a pressure of 8 MPa, fluid and wall temperatures ranging from 305 K to 390 K, and Reynolds numbers ranging from 0.1 to 35, show complex changes in flow and heat transfer. When simulations are repeated using the ideal gas law, Soave-Redlich-Kwong, and Peng-Robinson equations of state to the system, many of these effects are not fully captured. We compare the drastically different flow characteristics between non-ideal and ideal models as well as present on the computational cost of the varying degrees of accuracy.
*This work was facilitated though the use of advanced computational, storage, and networking infrastructure provided by the Hyak supercomputer system at the University of Washington. Funding also provided by by the Exascale Computing Project (17-SC-20-SC), a collaborative effort of two U.S. Department of Energy (DOE) organizations, the Office of Science and the National Nuclear Security Administration. The research was performed using computational resources sponsored by the Department of Energy's Office of Energy Efficiency and Renewable Energy and located at the National Renewable Energy Laboratory.
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