[FliegenderZirkus]

Originally Posted by Opaque

IAPWS is built into Ansys CFX. What would you need to code?

The built-in equilibrium steam model is unfortunately not compatible with evaporation from lagrangian droplets. When you try to set it up a bunch of errors are produced, such as that the Saturation Properties in the Homogeneous Binary Mixture dialogue must use the Antoine equation when evaporation is modelled, whereas the IAPWS of course uses tabular interpolation. I think you can't even select the water injection material as H2Ol (from IAPWS) because it must have a constant density. I'm not sure if I'm recalling these errors exactly right but the conclusion remains that it doesn't appear to be possible out of the box. The challenge is that in part of the domain the steam is wet, whereas in other it is superheated. And as the droplets evaporate, these regions are changing too. I was in contact with Ansys support about this and they actually suggested to try to replicate the equilibrium steam behavior via CCL expressions. But I'm nowhere near experienced enough to embark on such a task.

[Opaque]

Originally Posted by FliegenderZirkus

The built-in equilibrium steam model is unfortunately not compatible with evaporation from lagrangian droplets. When you try to set it up a bunch of errors are produced, such as that the Saturation Properties in the Homogeneous Binary Mixture dialogue must use the Antoine equation when evaporation is modelled, whereas the IAPWS of course uses tabular interpolation. I think you can't even select the water injection material as H2Ol (from IAPWS) because it must have a constant density. I'm not sure if I'm recalling these errors exactly right but the conclusion remains that it doesn't appear to be possible out of the box. The challenge is that in part of the domain the steam is wet, whereas in other it is superheated. And as the droplets evaporate, these regions are changing too. I was in contact with Ansys support about this and they actually suggested to try to replicate the equilibrium steam behavior via CCL expressions. But I'm nowhere near experienced enough to embark on such a task.

Got it. You want to use the non-equilibrium steam Eulerian model plus injection of Lagrangian particles with consistent material (IAPWS) in all the phases.

[FliegenderZirkus]

It's the other poster in this thread who's using non-equilibrium steam (zhanghuicheng@nnu.edu.cn). I'd be fine with equilibrium steam using IAPWS, but neither are compatible with evaporating Lagrangian sprays I'm afraid. Thank you for thinking about this though anyway.

[evcelica]

I know the restrictions for the droplets are for the liquid phase, and yes constant density is required. But I'm not aware of any restrictions on the gas phase? Perhaps you can use a more realistic (better than ideal gas) description for the gas phase and define liquid properties at your operating conditions. Perhaps real gas model, or maybe the IAWPS for the gas phase could work? Probably would have to make sure your saturation curve defined by your Antoine Coefficients doesn't leave any gaps where the gas phase will be missing properties, as that would crash the solver. With such a complex simulation, I highly doubt that "slightly off" material properties are going to be anywhere near the biggest source of inaccuracy in the model. I'd define the material properties as well as the program will allow and move forward with the simulation.