Change boundary condition during unsteady simulation

BigJoe · October 21, 2016, 18:49

Hello Engineers!

I want to change boudnary conditions like pressure or temperature during the unsteady simulation. For instance, temperature increase to 200K after 1s or 100 time steps. Usually what i do is to stop the simulation or set a certain time step and wait the simulation finished then change the BC to continue running....But I'm afraid this is not the best way to implement....Has anyone had the similar experience or successfully solved this issue?

Thank you!

AHF · October 23, 2016, 02:57

Quote:

Originally Posted by BigJoe

Hello Engineers!

I want to change boudnary conditions like pressure or temperature during the unsteady simulation. For instance, temperature increase to 200K after 1s or 100 time steps. Usually what i do is to stop the simulation or set a certain time step and wait the simulation finished then change the BC to continue running....But I'm afraid this is not the best way to implement....Has anyone had the similar experience or successfully solved this issue?

Thank you!

you can do it easily by UDF. use "if" condition for time to change is specific time.

LuckyTran · October 25, 2016, 13:34

If you are trying to simulate a step-change, I think stopping and changing the boundary condition is the best way to do it. This can easily be automated via TUI commands in a journal file.

If you have a transient temperature profile then I recommend to do a profile or UDF.

October 21, 2016, 18:49	Change boundary condition during unsteady simulation	#1
BigJoe New Member Join Date: Feb 2016 Posts: 20 Rep Power: 10	Hello Engineers! I want to change boudnary conditions like pressure or temperature during the unsteady simulation. For instance, temperature increase to 200K after 1s or 100 time steps. Usually what i do is to stop the simulation or set a certain time step and wait the simulation finished then change the BC to continue running....But I'm afraid this is not the best way to implement....Has anyone had the similar experience or successfully solved this issue? Thank you!

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October 25, 2016, 13:34		#3
LuckyTran Senior Member Lucky Join Date: Apr 2011 Location: Orlando, FL USA Posts: 5,672 Rep Power: 65	If you are trying to simulate a step-change, I think stopping and changing the boundary condition is the best way to do it. This can easily be automated via TUI commands in a journal file. If you have a transient temperature profile then I recommend to do a profile or UDF.