Learning Forum

[soloviev]

Hello,

We are running a multiphase VOF-to-DPM model currently, which models sea spray generation at an interface between air and water. We have recently implemented evaporation into this model as well. We are looking to also turn on the heat exchange model. We read about the models in the theory guide, and it seems the dual cell model would work as opposed to the macro model (since this is 1-D). Does the dual cell model work with multiphase? What other settings are suggested?

 

Thanks,

Alex

[Rob]

Dual cell is to add HX model as an overlay. I've never tried it with multiphase (or at all to be honest) but suspect it's not been coded with that in mind. What supplies the heat to evaporate the water?

[soloviev]

Right now we are trying to model evaporation under normal oceanic conditions, so the temperature of the water is fueling evaporation. Is this effective enough? We are still new to the evaporation model so may not be using it as effectively as possible either. 

 

Thanks,

Alex

[Amine Ben Hadj Ali]

What does exist in reality? Do you have heat exchanger at the water interface? What do you mean with implementation of evaporation model?

[soloviev]

We are simulating the air-sea interface under tropical cyclone conditions. We have the 3D rectangular domain filled partially with water and partially with air. We initialize waves at the interface and then set up periodic boundary conditions at the inlet and outlet. Tropical cyclone wind stress is applied at the top of the domain. We have the VOF to DPM model turned on to simulate sea spray generation. We have now turned on the evaporaiton-condensation model to evaporate droplets produced by the VOF to DPM. The water and air temperatures are set in the materials. 

As a next step we would also like to simulate heat and moisture exchange, so we are wondering the best way to do so. We are interested to see how evaporation of spray affects the thermo structure in the air. This involves heat and mass exchange at the air-water interface and evaporation and exchange of spray. 

What do you mean do we have heat exchanger at the water interface?

 

Thanks,

Alex

[Amine Ben Hadj Ali]

I did not understand why you asked after heat exchanger model that is my question.

So you are defining the mass transfer between the discrete particles and moist air?

For the Eulerian mass transfer you need to write about UDF based on Hertz Knudsen Like approach (work of Schrage is also helpful) to model interfacial evaporation.

The whole work is quite challenging and I guess I cannot suggest to handle DPM mass transfer in separate run or use a pure Eulerian approach.

Good Luck.

[soloviev]

Thank you for your input. 

 

Thanks,

Alex

[soloviev]

I have imported a STL that appears to have some sort of mesh to it (see image) but it Is still flat in the vertical direction. Is there a way to change this once in SpaceClaim or does this have to do with the import itself being corrupted?

 

 

Thanks,

Alex