Two boundary conditions in one patch

kraf · July 16, 2021, 00:51

Hello!

Newbie here.
I'm trying to simulate turbulent flow in a open channel. At the bottom of the channel, I want to define the following boundary conditions dU/dz=0 and U=0. Is there any boundary that can do that? It seems that I need to combine a zerogradient (dU/dz)+ fixedvalue (u=0). Does anybody has some idea?

Thank you in advance.

piu58 · July 16, 2021, 02:58

That does not work. These conditions contradict each other.

kraf · July 18, 2021, 19:05

Dear Uwe Pilz
Thank you for your reply.
I see. What about imposing one condition in one region and the other in the second region? I'm attaching a picture of what I would like to impose as boundary condition.
Thank you for your help in advance.

Kojote · July 19, 2021, 06:00

Hi, i do not know if this help but you can use swak4foam and teh use the groovyBCdirecton which is very powerfull. Maybe this fix your problem.

Br

Christian

July 16, 2021, 00:51	Two boundary conditions in one patch	#1
kraf New Member Ibaraki Join Date: Jul 2021 Posts: 9 Rep Power: 4	Hello! Newbie here. I'm trying to simulate turbulent flow in a open channel. At the bottom of the channel, I want to define the following boundary conditions dU/dz=0 and U=0. Is there any boundary that can do that? It seems that I need to combine a zerogradient (dU/dz)+ fixedvalue (u=0). Does anybody has some idea? Thank you in advance.

July 16, 2021, 02:58		#2
piu58 Senior Member Uwe Pilz Join Date: Feb 2017 Location: Leipzig, Germany Posts: 744 Rep Power: 15	That does not work. These conditions contradict each other. __________________ Uwe Pilz -- Die der Hauptbewegung überlagerte Schwankungsbewegung ist in ihren Einzelheiten so hoffnungslos kompliziert, daß ihre theoretische Berechnung aussichtslos erscheint. (Hermann Schlichting, 1950)

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
[OLAFLOW] The OLAFLOW Thread	Phicau	OpenFOAM Community Contributions	457	March 27, 2024 00:59
Centrifugal fan	j0hnny	CFX	13	October 1, 2019 13:55
Radiation in semi-transparent media with surface-to-surface model?	mpeppels	CFX	11	August 22, 2019 07:30
[mesh manipulation] Importing Multiple Meshes	thomasnwalshiii	OpenFOAM Meshing & Mesh Conversion	18	December 19, 2015 18:57
An error has occurred in cfx5solve:	volo87	CFX	5	June 14, 2013 17:44

July 19, 2021, 06:00		#4
Kojote Member Join Date: Aug 2011 Posts: 37 Rep Power: 14	Hi, i do not know if this help but you can use swak4foam and teh use the groovyBCdirecton which is very powerfull. Maybe this fix your problem. Br Christian