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xinquanzhoucn February 19, 2013 12:49

interfacial area concentraction UDS in Fluent 6.3 and 14.0

I am trying to do a two-phase flow simulation using interfacial area transport equations, however I have some problems.

I have some UDFs defining our own drag and lift models. However, these models are written with the interfacial area concentration embedded as a UDS. Certainly I have the code defining interfacial area concentration as a UDS because all these UDFs were written for Fluent 6.3.

However, I am using fluent 14.0, in which the interfacial area concentration model was already embedded. I don't need to add a UDS for interfacial area concentration. But I don't know how to implement the UDFs of drag and lift since the interfacial area concentration was still used as UDS rather than an existing model or macro in fluent.

I am not sure if I stated my problems clearly or not. Please let me know if anyone can help. Thx!!

Harry321 January 20, 2015 17:02

Hi, Did you figure out how to do this?

I would like to modify interfacial area concentration and there is a possibility in GUI to add UDF but I cannot find how the macro in fluent for interfacial area should looks like.

SJSW March 30, 2016 23:52


I think you could try check IAC and choose the models.

I tried to use a udf for the diameter of the second phase for a bottom-blowing model in ANSYS14.
The diameter changed with the absolute pressure.
In the first place, it worked. However, when some air was added into the domain, which means that the domain was not full of water, the calculation diverged.

Should I check IAC (Interfacial area concentration) and set up the Min or Max diameter?
Another question is when should IAC be used? Along with PBM(population Balance Model) or diameter udf? @@

Thank you!

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