unsteady behavior for a scalar with non-temporal source definition and steady BC?

alinik · December 27, 2017, 18:45

Hi everyone,

I have defined a source term for a scalar that is not a function of time and the boundary conditions are also steady while, for some reason, the simulation is transient.
The results show that this particular scalar has transient behavior while, as I said, the boundary condition and the source term do not have temporal terms.

What could be the reason?

Thanks,
Ali

AlexanderZ · December 27, 2017, 21:30

you may try to calculate it only once, on the first time step

best regards

alinik · December 28, 2017, 15:49

I will do it and let you know what will happen.
But wouldn't it get transported downstream if the source is turned-off after the first time-step?

AlexanderZ · December 28, 2017, 20:39

if under scalar you mean uds variable, than there should be no problem with such approach.
Once you calculate it, uds will store data.

Best regards

December 27, 2017, 18:45	unsteady behavior for a scalar with non-temporal source definition and steady BC?	#1
alinik Senior Member ali Join Date: Oct 2009 Posts: 318 Rep Power: 18	Hi everyone, I have defined a source term for a scalar that is not a function of time and the boundary conditions are also steady while, for some reason, the simulation is transient. The results show that this particular scalar has transient behavior while, as I said, the boundary condition and the source term do not have temporal terms. What could be the reason? Thanks, Ali

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December 27, 2017, 21:30		#2
AlexanderZ Senior Member Alexander Join Date: Apr 2013 Posts: 2,363 Rep Power: 34	you may try to calculate it only once, on the first time step best regards

December 28, 2017, 15:49		#3
alinik Senior Member ali Join Date: Oct 2009 Posts: 318 Rep Power: 18	I will do it and let you know what will happen. But wouldn't it get transported downstream if the source is turned-off after the first time-step?

December 28, 2017, 20:39		#4
AlexanderZ Senior Member Alexander Join Date: Apr 2013 Posts: 2,363 Rep Power: 34	if under scalar you mean uds variable, than there should be no problem with such approach. Once you calculate it, uds will store data. Best regards