[Poimsm]

Hello!,

In the evaporation-condensation model or Lee model, does the saturation temperature correspond to the dew point (5°C) or the boiling point (100°C)?

I'm trying to model the mud drying process at room temperature with a stream of dry air. I'm using the Eulerian model with the evaporation-condensation model activated.

[tahar]

it is related to boiling point
you must use UDF for saturation temperature at room temperature use antoine equation then hooks your udf to lee model in fluent panel
you can also use speices mass transfert udf

[tahar]

also i think your drying process will be by water diffussion not boiling and if you are using dray air you must taking account the advection term (not included in fluent models)

i think there exist equation named CARRIES equation to simulte your mass transfert

[Poimsm]

Hello, thanks for the response

I also think that the problem should be modeled as a diffusion in the interface.

If I were to use the boiling model and set a "low" saturation temperature for evaporation, the mud would remain at that constant temperature during the phase change process, and the relative humidity of the air would not be taken into account.

On the other hand, natural evaporation occurs at any temperature below the boiling point. There is no particular evaporation temperature similar to the dew point for condensation.

My question is: in what way can I model the water diffusion at the interface without using UDF?

I currently have a two phase model:

• Liquid phase with species: mud + liquid water
  
• Gaseous phase with species: air + water vapor

My case is not a flat surface that evaporates water, but a 3D model of a horizontal mud mixer blown by a dry air stream.

[tahar]

IF you do not use udf DEFINE MASS TRANSFERT you have to use speices mass transfert model
you should create :
let say mixture_one template with two speices(mud + liquid water)
and mixture_two template with two speices also (air + water vapor)
mass transfert will be form liquid water speices to vapor for example