How to write a udf to define average temperature at one boundary based on the value o

er_ijaz · May 4, 2021, 04:14

Hi all,
I remember udf is used to define profile.
Currently I need to 'input' the value at one boundary condition based on the value at another boundary.
For example
Avg (T)@inlet=Avg(T)@outlet+14
So each iteration/timestep my temperature at inlet has to be adjusted based on outlet.
Note: I'm aware of 'expression' but since my number of inlets and outlets are around 70, it is taking longer duration to build the model. Hence I'm planning to use udf
Which DEFINE_MACRO I need to use?
How to compute average velocity at other boundary (or location) and use it here?
Thank you

AlexanderZ · May 5, 2021, 22:43

to define boundary condition you need DEFINE_PROFILE macro

you may check Ansys Fluent Customization manual -> DEFINE_ON_DEMAND
to get an example how to get average temperature on surface, and change it to velocity

May 4, 2021, 04:14	How to write a udf to define average temperature at one boundary based on the value o	#1
er_ijaz Member ijaz fazil Join Date: Apr 2013 Location: Singapore Posts: 73 Rep Power: 13	Hi all, I remember udf is used to define profile. Currently I need to 'input' the value at one boundary condition based on the value at another boundary. For example Avg (T)@inlet=Avg(T)@outlet+14 So each iteration/timestep my temperature at inlet has to be adjusted based on outlet. Note: I'm aware of 'expression' but since my number of inlets and outlets are around 70, it is taking longer duration to build the model. Hence I'm planning to use udf Which DEFINE_MACRO I need to use? How to compute average velocity at other boundary (or location) and use it here? Thank you

May 5, 2021, 22:43		#2
AlexanderZ Senior Member Alexander Join Date: Apr 2013 Posts: 2,363 Rep Power: 34	to define boundary condition you need DEFINE_PROFILE macro you may check Ansys Fluent Customization manual -> DEFINE_ON_DEMAND to get an example how to get average temperature on surface, and change it to velocity __________________ best regards ****************************** press LIKE if this message was helpful

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