Water flow in a spiral like tube

iDeew · May 29, 2012, 12:09

Hi everybody,
I'm trying to simulate a flow of water in a tube with 3 U bends. Please check the below figure.

Why is the liquid flows outside the steel tube near the first U bend?

abdul099 · May 30, 2012, 03:08

Maybe a hole in your geometry? Have you checked it to be closed before meshing? Is your mesh resolution capable to catch the U-bend accordingly or could it intersect with the wrong surface when taking the interface tolerance into account?

iDeew · May 31, 2012, 10:51

so do you think a finer mesh size will solve the problem?

Link to sim file: https://docs.google.com/file/d/0B43E...8ya3JIdWc/edit

Thank you

abdul099 · May 31, 2012, 14:40

Can't access the file. You need to set some permissions.

iDeew · May 31, 2012, 15:50

Hope you can download the file now

Thank you

abdul099 · May 31, 2012, 16:17

Got it, I'm looking on it right now.

iDeew · June 13, 2012, 11:34

Any idea on whats going on?

Thank you

Pauli · June 13, 2012, 15:38

Is the problem with the streamline generation? Looks like the time step is too large.

abdul099 · June 15, 2012, 15:32

Uuupps, sorry. Totally forgot to write an answer.
The issue is not the streamline generation, it's the crap model setup (sorry, I have to say that). The air box and the solid share partly the same volume and I think the interfaces are not set right.
I'm sorry I don't have a picture right now. I will post it within the next one or two days. I promise!

abdul099 · June 18, 2012, 14:50

Okay, now I've got the pictures. The first two pictures are showing your setup: The air region (blue) overlays the steel region (green). Also the interfaces are not right. The water region touches the inner wall of the steel region, so far no issue. But also the air region touches the inner wall of the steel region. This is no proper setup. The air region should touch the outer wall of the steel region.
This is causing an interface between water region and the air region, causing the water to pass "through" the steel.

The third pictures shows the setup how it should look like: Outer wall of the water region touches the inner wall of the steel region, the outer wall of the steel region touches the inner wall of the air region.

You need to subtract the steel region from the air region and create new interfaces.

iDeew · June 19, 2012, 12:17

I created a straight tube with interfaces.
Is this the correct way to do it?

https://docs.google.com/open?id=0B43...jU1ZXBYR09HOWM

Thank you for time

May 30, 2012, 03:08		#2
abdul099 Senior Member Join Date: Oct 2009 Location: Germany Posts: 636 Rep Power: 21	Maybe a hole in your geometry? Have you checked it to be closed before meshing? Is your mesh resolution capable to catch the U-bend accordingly or could it intersect with the wrong surface when taking the interface tolerance into account? __________________ We do three types of jobs here: GOOD, FAST AND CHEAP You may choose any two!

May 31, 2012, 10:51		#3
iDeew New Member IDW Join Date: Apr 2012 Posts: 24 Rep Power: 14	so do you think a finer mesh size will solve the problem? Link to sim file: https://docs.google.com/file/d/0B43E...8ya3JIdWc/edit Thank you Last edited by iDeew; May 31, 2012 at 12:25.

May 31, 2012, 14:40		#4
abdul099 Senior Member Join Date: Oct 2009 Location: Germany Posts: 636 Rep Power: 21	Can't access the file. You need to set some permissions. __________________ We do three types of jobs here: GOOD, FAST AND CHEAP You may choose any two!

May 31, 2012, 16:17		#6
abdul099 Senior Member Join Date: Oct 2009 Location: Germany Posts: 636 Rep Power: 21	Got it, I'm looking on it right now. iDeew likes this. __________________ We do three types of jobs here: GOOD, FAST AND CHEAP You may choose any two!

June 15, 2012, 15:32		#9
abdul099 Senior Member Join Date: Oct 2009 Location: Germany Posts: 636 Rep Power: 21	Uuupps, sorry. Totally forgot to write an answer. The issue is not the streamline generation, it's the crap model setup (sorry, I have to say that). The air box and the solid share partly the same volume and I think the interfaces are not set right. I'm sorry I don't have a picture right now. I will post it within the next one or two days. I promise! __________________ We do three types of jobs here: GOOD, FAST AND CHEAP You may choose any two!

May 31, 2012, 15:50		#5
iDeew New Member IDW Join Date: Apr 2012 Posts: 24 Rep Power: 14	Hope you can download the file now Thank you

June 13, 2012, 11:34		#7
iDeew New Member IDW Join Date: Apr 2012 Posts: 24 Rep Power: 14	Any idea on whats going on? Thank you

June 13, 2012, 15:38		#8
Pauli Senior Member Pauli Join Date: Mar 2009 Posts: 189 Rep Power: 17	Is the problem with the streamline generation? Looks like the time step is too large.

June 19, 2012, 12:17		#11
iDeew New Member IDW Join Date: Apr 2012 Posts: 24 Rep Power: 14	I created a straight tube with interfaces. Is this the correct way to do it? https://docs.google.com/open?id=0B43...jU1ZXBYR09HOWM Thank you for time

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