How to initialize with different velocity at top and bottom half of domain

quarkz · October 6, 2024, 22:27

Hi, I'm trying to solve a flow past cylinder problem whereby the top and bottom half of the domain have slightly different velocity of 1.2 and 0.8 m/s

For the inlet BC, I separated it into top and bottom inlet and gave 1.2 and 0.8 m/s.

But regarding the domain, how do I initialize it? I read in the forum that an add-on like groovyBC or swak4Foam can do it but in the past, I have problems with installing them.

So what's the easiest way to achieve this? Btw, I'm using v22.06 but 23 and 24 ver are ok too.

Thanks!

samisafarini · October 7, 2024, 06:03

I think what you need to do is to use the setFields command, have a look at this tutorial https://doc.cfd.direct/openfoam/user-guide-v8/dambreak, i know its for openfoam8 but I think it should work with your version too.

Could you share your model with this forum just to be abit clearer with the requirements?

It would be good to move this thread to openfoam pre-processing.

quarkz · October 10, 2024, 10:20

Hi samisafarini,

Thanks, I think it should work. I managed also to install swakFoam on my own PC and get the solution initialized. I can then move it to the cluster for calculation

Here's the command for swakFoam:

funkySetFields -case cylinder2D_asym_1.2_0.8_fk -time 0 -field U -keepPatches -expression "pos().y <= 0 ? vector (0.8, 0, 0) : vector (1.2, 0, 0)"

October 6, 2024, 22:27	How to initialize with different velocity at top and bottom half of domain	#1
quarkz Senior Member TWB Join Date: Mar 2009 Posts: 414 Rep Power: 19	Hi, I'm trying to solve a flow past cylinder problem whereby the top and bottom half of the domain have slightly different velocity of 1.2 and 0.8 m/s For the inlet BC, I separated it into top and bottom inlet and gave 1.2 and 0.8 m/s. But regarding the domain, how do I initialize it? I read in the forum that an add-on like groovyBC or swak4Foam can do it but in the past, I have problems with installing them. So what's the easiest way to achieve this? Btw, I'm using v22.06 but 23 and 24 ver are ok too. Thanks!

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October 7, 2024, 06:03		#2
samisafarini New Member Sami Safarini Join Date: Sep 2021 Posts: 11 Rep Power: 5	I think what you need to do is to use the setFields command, have a look at this tutorial https://doc.cfd.direct/openfoam/user-guide-v8/dambreak, i know its for openfoam8 but I think it should work with your version too. Could you share your model with this forum just to be abit clearer with the requirements? It would be good to move this thread to openfoam pre-processing.

October 10, 2024, 10:20		#3
quarkz Senior Member TWB Join Date: Mar 2009 Posts: 414 Rep Power: 19	Hi samisafarini, Thanks, I think it should work. I managed also to install swakFoam on my own PC and get the solution initialized. I can then move it to the cluster for calculation Here's the command for swakFoam: funkySetFields -case cylinder2D_asym_1.2_0.8_fk -time 0 -field U -keepPatches -expression "pos().y <= 0 ? vector (0.8, 0, 0) : vector (1.2, 0, 0)"