Can Fluent Import New Turbulence Model By UDF?

November 29, 2005, 22:57

hi,

I have a new turbulence model, and I want to import it to Fluent by UDF.

Can I do it successfully? If so, how can I do it?(Give some advices)

Thanks!

Andy

pratikddhoot · March 24, 2016, 14:42

Hi, If you have successfully imported a model, I would like to know how. I am struggling on the same issue right now.

LuckyTran · March 25, 2016, 13:56

This problem is too general for specific answers to be given.

In general, you can make Fluent do anything you want with a UDF. But implementation is specific to what you are trying to do. It depends exactly on what your turbulence model is that you are trying to import. Most models can be implemented just by hooking up a udf for the turbulent viscosity. But the complexity arises from how you want to model the turbulent viscosity. In particular, the model for turbulent viscosity is different for high Re and low Re models.

pratikddhoot · March 25, 2016, 14:09

While I understand that I just have to play with turbulent viscosity in UDF as required in my model, I am trying to modify the Spalart Allmaras model into a zero equation model with a function for turbulent viscosity at each grid cell. Is this doable and what changes will be necessary to convert a 1-eq model to a 0-eq model?

Thanks,
Pratik

LuckyTran · March 25, 2016, 14:14

In the Fluent customization manual, there is an example you can follow.2.3.44. DEFINE_TURBULENT_VISCOSITY

November 29, 2005, 22:57	Can Fluent Import New Turbulence Model By UDF?	#1
Andy Cong Guest Posts: n/a	hi, I have a new turbulence model, and I want to import it to Fluent by UDF. Can I do it successfully? If so, how can I do it?(Give some advices) Thanks! Andy

March 25, 2016, 14:14		#5
LuckyTran Senior Member Lucky Join Date: Apr 2011 Location: Orlando, FL USA Posts: 5,761 Rep Power: 66	In the Fluent customization manual, there is an example you can follow.2.3.44. DEFINE_TURBULENT_VISCOSITY pratikddhoot likes this.

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March 24, 2016, 14:42		#2
pratikddhoot New Member Pratik Dhoot Join Date: Mar 2016 Location: Boston, MA Posts: 20 Rep Power: 10	Hi, If you have successfully imported a model, I would like to know how. I am struggling on the same issue right now.

March 25, 2016, 13:56		#3
LuckyTran Senior Member Lucky Join Date: Apr 2011 Location: Orlando, FL USA Posts: 5,761 Rep Power: 66	This problem is too general for specific answers to be given. In general, you can make Fluent do anything you want with a UDF. But implementation is specific to what you are trying to do. It depends exactly on what your turbulence model is that you are trying to import. Most models can be implemented just by hooking up a udf for the turbulent viscosity. But the complexity arises from how you want to model the turbulent viscosity. In particular, the model for turbulent viscosity is different for high Re and low Re models.

March 25, 2016, 14:09		#4
pratikddhoot New Member Pratik Dhoot Join Date: Mar 2016 Location: Boston, MA Posts: 20 Rep Power: 10	While I understand that I just have to play with turbulent viscosity in UDF as required in my model, I am trying to modify the Spalart Allmaras model into a zero equation model with a function for turbulent viscosity at each grid cell. Is this doable and what changes will be necessary to convert a 1-eq model to a 0-eq model? Thanks, Pratik