[FliegenderZirkus]

I have a steam turbine simulation which uses the Equilibrium wet steam material model, so a Homogeneous Binary Mixture of water in vapor and liquid phases with properties from IAPWS-IF97. This works very well. Now I would like to enhance the model by adding a water spray via Lagrangian particle tracking. I am primarily interested in the thermal effect of the evaporating water droplets. For example, if the liquid water is sprayed into a region where the steam is superheated, I would like to see how the droplets evaporate and cool the steam down into the wet steam state. I understand that the equilibrium steam is incompatible with the evaporating droplets model. Is that correct? The only way how I see such a simulation to be feasible is to approximate the fluid as an ideal gas. Then I can indeed evaporate the droplets into it. But this is a big inaccuracy, especially in terms of the temperature field, because the condensation latent heat from the main flow expansion is not accounted for. Is there a better way to do this? Thanks for any hints.

[ghorrocks]

This is a complex question and not an area I have much expertise in.

If you are trying to model the cooling effect of injecting water droplets into an existing multiphase steam model, then why not just inject some water droplet phase material at the temperature you want? Why do you need a lagrangian model for this?

I do not know whether you can run a eularian multiphase model with a lagrangian model as well when boiling/condensation is happening in both models. But as I said before, this appears to be an unnecessary complication - choose either a eularian or a lagangian approach and do everthing in that framework.

[FliegenderZirkus]

The equilibrium wet steam material model assumes that the equilibrium composition of wet steam for a given state (pressure, temperature or enthalpy) is achieved instantaneously. So injecting a pure eulerian liquid water would probably cool down the area close to the injector very much, plus lead to other non-physical results. But it's worth trying, thanks for the tip. In reality, the droplets have a finite lifetime and can travel quite far. On top of that, at one point I'll be interested in erosion damage from the droplets that haven't evaporated, for which the Lagrangian approach is needed. So the best option I see now is to have the Eulerian part as single phase (either ideal gas or some other material model) and evaporate the particles into it, accepting the inaccuracies.

[zhanghuicheng@nnu.edu.cn]

Originally Posted by FliegenderZirkus

I have a steam turbine simulation which uses the Equilibrium wet steam material model, so a Homogeneous Binary Mixture of water in vapor and liquid phases with properties from IAPWS-IF97. This works very well. Now I would like to enhance the model by adding a water spray via Lagrangian particle tracking. I am primarily interested in the thermal effect of the evaporating water droplets. For example, if the liquid water is sprayed into a region where the steam is superheated, I would like to see how the droplets evaporate and cool the steam down into the wet steam state. I understand that the equilibrium steam is incompatible with the evaporating droplets model. Is that correct? The only way how I see such a simulation to be feasible is to approximate the fluid as an ideal gas. Then I can indeed evaporate the droplets into it. But this is a big inaccuracy, especially in terms of the temperature field, because the condensation latent heat from the main flow expansion is not accounted for. Is there a better way to do this? Thanks for any hints.

Hello, Sir. It's truly inspiring to find a fellow researcher specializing in steam turbine condensation phenomena. My current focus involves non-equilibrium steam condensation modeling, with forthcoming investigations planned on Lagrangian-based analysis of water injection cooling effects across blade surfaces and exhaust passages. However, I'm encountering persistent divergence in computational results regarding non-equilibrium phase transition dynamics. Would you be willing to share an academic email or WeChat contact? I believe cross-verification of our multiphase coupling mechanisms could prove mutually beneficial.