A novel numerical approach for simulating low-pressure and high-pressure non-equilibrium condensation in real gases

This paper presents a novel numerical approach for simulating rapidly expanding condensing flows across a wide range of thermodynamic conditions, including low-pressure steam, high-pressure steam, and supercritical carbon dioxide. The condensation model considers the non-ideality of the gas during droplet nucleation, and a modified kinetic Hertz-Knudsen droplet growth rate model is proposed. Real gas properties in the supercritical, superheated, and metastable regions are obtained using an in-house Python code and incorporated into the solver via User-Defined Functions as external look-up tables. The numerical model is extensively tested to demonstrate its accuracy and validity, and the results exhibit excellent agreement with experimental data. The model has been implemented in a commercial CFD solver, making it suitable for a range of applications and fluids.