porosity in UDF

February 22, 2004, 12:40

Hello, I have a question about prosity. Can I modify the porosity to be dependent on pressure in UDF? How to use the porosity in UDF? I can't find this variable in UDF guide.

Thank you!

Jin

February 22, 2004, 13:02

I had a quick look at the documentation myself, but I couldn't find a way of setting the porosity either. However, when I come to simulate a porous zone I tend to write my own UDF's rather than the fluent built in ones. The fluent porous models are simply momentum sinks in the source terms for x y and z momentum. If you write your own porous model you can set porosity to whatever you want.

Just a thought.

February 23, 2004, 06:05

hi jinyan,

add the following macro into your udf and you can use it just as C_U, C_P, and etc.

#define C_POR(c,t) C_STORAGE_R(c,t,SV_PRO)

However, I am not sure of its validation. You should do some tests by youself.

good luck.

February 23, 2004, 18:51

You can alter porosity with a DEFINE_PROFILE UDF. (the Fluent manual tells you to use DEFINE_PROPERTY which doesn't work). In your UDF, make it a function of pressure.

WSWGg · December 1, 2009, 10:27

Use C_PROFILE function DEFINE_PROFILE UDF, it works - I tested.

February 22, 2004, 12:40	porosity in UDF	#1
Jin Yan Guest Posts: n/a	Hello, I have a question about prosity. Can I modify the porosity to be dependent on pressure in UDF? How to use the porosity in UDF? I can't find this variable in UDF guide. Thank you! Jin

February 22, 2004, 13:02	Re: porosity in UDF	#2
Andrew Garrard Guest Posts: n/a	I had a quick look at the documentation myself, but I couldn't find a way of setting the porosity either. However, when I come to simulate a porous zone I tend to write my own UDF's rather than the fluent built in ones. The fluent porous models are simply momentum sinks in the source terms for x y and z momentum. If you write your own porous model you can set porosity to whatever you want. Just a thought.

February 23, 2004, 06:05	Re: porosity in UDF	#3
ccc Guest Posts: n/a	hi jinyan, add the following macro into your udf and you can use it just as C_U, C_P, and etc. #define C_POR(c,t) C_STORAGE_R(c,t,SV_PRO) However, I am not sure of its validation. You should do some tests by youself. good luck.

February 23, 2004, 18:51	Re: porosity in UDF	#4
Craig Guest Posts: n/a	You can alter porosity with a DEFINE_PROFILE UDF. (the Fluent manual tells you to use DEFINE_PROPERTY which doesn't work). In your UDF, make it a function of pressure.

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December 1, 2009, 10:27		#5
WSWGg New Member Igor Join Date: Nov 2009 Location: Saint-Petersburg Posts: 8 Rep Power: 17	Use C_PROFILE function DEFINE_PROFILE UDF, it works - I tested.