Learning Forum

[chhotelal prajapati]

Hello Friends,

Could you please tell me, how to use the moisture transport phenomena by using the user define scaler (UDS) function with Euler Two fluid Model (TFM).

I have tried but it is not Initialization. 

[Rob]

Please can you clarify the question? Why do you need a UDS for the Eulerian multiphase model? Do you need a multiphase model? 

[chhotelal prajapati]

Dear Rob, I am working on a drying mechanism, such as moisture transport in the form of vapor from solid to air with TFM in Eulier-Eulier. In this case, I applied TFM in the E-E model and also applied UDS for the moisture source, and UDF for the moisture Inlet, update moisture content, and energy source term. but the problem is when the initialized the problem always error occurs:  F1 process could not be started. I don't what is happening. Do you have solution for it. or other method to do that process such as species transport with E-E model.

[Rob]

OK, so you have vapour tracked in the solid as a scalar? Makes sense as you can't have flow in a solid zone. 

At the edge of the solid does the scalar get added to the gas phase or as a liquid? If it's the former, why do you need a multiphase model? 

Are you using a UDF? 

[chhotelal prajapati]

multi-phase model to use the momentum exchange between the phases is also dependent upon the type of mixture being modeled. owing to the E-E model we can use the heat and mass transfer phenomena between the two-phase fluid and solid. moisture being removing the solid and liquid is transport in the form of vapour from the air.

[Rob]

Except in the solid zone there is no fluid. Phase change from liquid to gas isn't a problem. Getting and fluid from the "solid" zone is. 

[chhotelal prajapati]

This is not my problem, my problem is in the multiphase E-E model when we define the mass transfer mechanism between the interface between the fluid and solid the Error coming F1 process could not be started. also, I do not understand where to define the moisture source and energy source and UDS.

[Rob]

How are you adding liquid into the fluid zone? 

[chhotelal prajapati]

Add the material solid granular as a liquid in the fluid zone, and define the material properties. you did not tell me how the solve the problem, if you know the multiphase flow E-E model then please reply.

[Rob]

You want to melt granular phase to liquid and then evaporate it? Please explain clearly what you're trying to do, with pictures. 

[chhotelal prajapati]

No, moisture is transported by convection by hot air owing to the diffusion.  

[Rob]

Yes, and where does the moisture come from? Please explain clearly what you're trying to do, with pictures. 

[chhotelal prajapati]

 

Solid, one of the Phases is content partial moisture content (suppose 20%).

I want to solve the mass transfer problem in the E-E multi-phase model. 

 

[Rob]

Post a sketch of what you're trying to do.