Learning Forum

[Majid Panahi]

Hello everyone

I want to added PCM to my simulation about drying of moist porous.but because I use the eulearian model I can't use Melting and Solidification, please help me that How to creat udf for this problem.

[Rob]

It depends. What exactly are you trying to do? Ie remove moisture from a solid phase, melt the solid etc. As it's a UDF we can give you some pointers to macros in the manual, but won't be writing or checking code. 

[Majid Panahi]

 

Thanks for your reply

In my simulation, warm air without moisture hits the moist porous medium, which causes the moisture of the porous medium to decrease. And the exhaust air becomes humid.

I simulated with the Eulerian model, now I want to increase the evaporation speed using PCM, so that first the PCM microcapsules melt, then it plays the role of a heat source and accelerates drying.

But not active the Melting option

Can you help me how to creat udf for added the PCM?

 

[Rob]

Do the PCM materials melt and then flow, or is each particle a shell containing PCM? I can only offer pointers to the documentation and suggest macros to read up on & potentially use. 

[Majid Panahi]

Thanks for you replay

The following steps for about pcm

[Majid Panahi]

First PCM give heat and melt then release heat and convert to solid it means the PCM only play the role of heat sinke and heat source 

[Rob]

So it's fully encapsulated. You can use a phase exchange model to move from one solid phase to another, use the material properties to account for melting energy. Or you can use a single granular phase and alter the specific heat capacity to mimic the phase change enthalpy. 

Have a look at the phase interaction models and for the latter, DEFINE_SPECIFIC_HEAT in the UDF manual (search in Help). 

[Majid Panahi]

Does your mean about DEFINE_SPECIFIC_HEAT in the UDF manual is the following search result?

[Rob]

Search for DEFINE_SPECIFIC_HEAT in the UDF (Customisation) manual, the results above are all from the User's Guide. I'm not sure where you're looking to get returns from multiple versions. 

[Majid Panahi]

Thanks for your reply

can you send pictuer of DEFINE_SPECIFIC_HEAT in the UDF (Customisation) manual or send direct link?

[Rob]

https://ansyshelp.ansys.com/account/Secured?returnurl=/Views/Secured/corp/v232/en/flu_udf/flu_udf_ModelSpecificDEFINE.html%23flu_udf_sec_define_sp_heat

[Majid Panahi]

Thanks

I chek the above link description and reply to you