User Defined Function in FLUENT

Waqas Ahmed · May 8, 2012, 16:03

Hello,

I am writing a udf on C.. for change in material property using command
DEFINE_PROPERTY

can i also use the command DEFINE_SOURCE for change in momentum equation in the same program?

Ankur T. · July 12, 2018, 08:33

I have written a UDF for adding the source term in the momentum equation for porous media.
But I am not able to understand how to put the value of the constant (C2)of Inertial Losses in Porous Media in my UDF.

Should I choose it randomly or there is some way available?

Kindly help!

pakk · July 17, 2018, 03:55

Hi Ankur,

This is not really a Fluent question, but a physics question. You found an equation somewhere that relates to porous media, and that equation includes a constant C_2.

To know what this constant C_2 is, you should not ask Fluent, or us, but the person who wrote the equation! Look in the text above or below the equation, maybe it is explained there?

Ankur T. · July 29, 2018, 07:43

I have a very basic issue that when we add source term in momentum equations for porous media using UDF compilation then How the UDF will decide the location of the porous medium in my Fluid domain?

Although when we give viscous and inertial resistance values in porous media option, there we directly select the cell zone ( from cell zone condition).

Kindly help!

May 8, 2012, 16:03	User Defined Function in FLUENT	#1
Waqas Ahmed New Member Waqas Ahmed Join Date: Feb 2011 Posts: 18 Rep Power: 15	Hello, I am writing a udf on C.. for change in material property using command DEFINE_PROPERTY can i also use the command DEFINE_SOURCE for change in momentum equation in the same program?

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July 17, 2018, 03:55		#3
pakk Senior Member Join Date: Nov 2013 Posts: 1,965 Rep Power: 26	Hi Ankur, This is not really a Fluent question, but a physics question. You found an equation somewhere that relates to porous media, and that equation includes a constant C_2. To know what this constant C_2 is, you should not ask Fluent, or us, but the person who wrote the equation! Look in the text above or below the equation, maybe it is explained there?

July 29, 2018, 07:43		#4
Ankur T. New Member Ankur Join Date: Nov 2017 Posts: 3 Rep Power: 8	I have a very basic issue that when we add source term in momentum equations for porous media using UDF compilation then How the UDF will decide the location of the porous medium in my Fluid domain? Although when we give viscous and inertial resistance values in porous media option, there we directly select the cell zone ( from cell zone condition). Kindly help!