integrate mass flow rate over time in new variable

Svetlana · March 25, 2025, 15:13

Hi, please see https://www.cfd-online.com/Forums/fl...ost881328.html I would like to move it to this forum section, but don't see a button to do it.

Trying to define a custom variable which varies with space. The goal is to track how much fluid entered at inlet (as distribution, i.e. different in each point, not only 1 number)

Tried to add user defined scalar with confusing results

Tried uds + udf with less confusing results, but still not looking reasonable

Details at the link above

Thanks in advance for your help.

Svetlana · March 25, 2025, 15:20

kind of solved it by apu=0, at least it is linear decrease now - will now need to define non-constant as next step - i will keep you updated. (didn't understand what apu 'central coefficient' term is for)

March 25, 2025, 15:13	integrate mass flow rate over time in new variable	#1
Svetlana Senior Member Svetlana Tkachenko Join Date: Oct 2013 Location: Australia, Sydney Posts: 423 Rep Power: 15	Hi, please see https://www.cfd-online.com/Forums/fl...ost881328.html I would like to move it to this forum section, but don't see a button to do it. Trying to define a custom variable which varies with space. The goal is to track how much fluid entered at inlet (as distribution, i.e. different in each point, not only 1 number) Tried to add user defined scalar with confusing results Tried uds + udf with less confusing results, but still not looking reasonable Details at the link above Thanks in advance for your help.

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March 25, 2025, 15:20		#2
Svetlana Senior Member Svetlana Tkachenko Join Date: Oct 2013 Location: Australia, Sydney Posts: 423 Rep Power: 15	kind of solved it by apu=0, at least it is linear decrease now - will now need to define non-constant as next step - i will keep you updated. (didn't understand what apu 'central coefficient' term is for)