RANS modelling of sonic CO2 jets

Considerable cross-disciplinary efforts are currently addressing the likely consequences of accidental releases from pressurised CO2 pipelines to be used in carbon capture and storage applications. Accurate prediction of discharge rate, condensed phase and the subsequent atmospheric dispersion of CO2 from such accidental releases is necessary to quantify all the hazard consequences, and forms the basis for emergency response planning and in determining minimum safe distances to populated areas. Pivotal to obtaining accurate predictions from numerical simulations is the correct choice of an equation of state. In this paper, we present a novel composite equation of state method implemented into a RANS model, with the equation set closed by a compressibility-corrected k- turbulence model. We demonstrate the improved performance of the new composite method over ideal and Peng-Robinson equations of state, and attribute the improvements to the accurate treatment of condensed phase CO2, present in such accidental releases.