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-   -   Moving mesh with butterfly valve (http://www.cfd-online.com/Forums/cfx/69390-moving-mesh-butterfly-valve.html)

uorinopuot October 21, 2009 10:24

Moving mesh with butterfly valve
 
Hello. I have been modelling a butterfly valve on cfx 12. I try to make the valve rotate by some range of angles but i cannot make it since in the options there are only displacement and location. I used displacement under cylindrical coordinates and i managed to get deformation around the axis i wanted but half the valve was going up and half down, ie not rotating. Any ideas?

ghorrocks October 21, 2009 17:19

Do I understand you by saying the valve does not rotate (eg a throttle butterfly in a car) but has two sections which rotate in different directions to throttle the flow? An image might help explain what you mean.

Assuming you are talking about a twin-pivot butterfly, I see several options:
1) Use one rotating frame of reference for the top valve and another for the bottom.
2) Use the immersed solid feature
3) Use deforming mesh - this would be quite difficult to do and it does not appear to be the best option.

uorinopuot October 21, 2009 17:38

Hello,

No the valve is a single one. I just tried to describe it as two parts each on one side of the axis. Anyway, I looked further into it and now what i did was to create a second domain (solid) which is the valve. I made a domain interface between the fluid and the valve and now i have a different problem. I use moving mesh and at the same time try to rotate the domain of the valve. Only that rotates though, not the fluid domain...
What i have looks mich like the bottom bit from this page.
http://www.ansys.com/assets/tech-bri...oving-mesh.pdf

Thanks

ghorrocks October 21, 2009 21:39

I see, you are modelling a normal butterfly valve then.

You do not want to model the valve as a solid. That will not work (unless you use the immersed solid feature).

My recommendations are still unchanged:
1) Use a rotating frame of reference for the valve and connect it to the rest of the passage with a GGI OR
2) Use the immersed solid feature OR
3) Use a deforming mesh.

Which is the best option will depend on exactly what you are modelling.

uorinopuot October 24, 2009 09:22

Okay I'll see what i can do. Thanks lot

songxguan November 1, 2009 07:30

Quote:

Originally Posted by uorinopuot (Post 233891)
Okay I'll see what i can do. Thanks lot

ghorrocks is right,
you can build two domain, one is flow field without valve, and the other one is a circle domain containing butterfly valve, then connect them with GGI. and then, what you should do is write a CEL to control the domain containing valve to rotate a expected angle.

some details you can refer to a journal paper:
<Dynamic analysis of three-dimensional flow in the opening process of a single-disc butterfly valve>
http://www.springerlink.com/content/vq5472u30686p9w6/

euzinho May 28, 2010 05:54

butterfly valve
 
Hi dear
I am trying to solve the same problem but using fluent, and I donīt have any idea how to do in order to get it done...
How can I make this valve rotate?

any help?

thanks in advance

euzinho May 28, 2010 05:58

butterfly valve
 
1 Attachment(s)
I take this oportunity to upload the model by .jpg
so, I wonder how to rotate the valve
thanks

ghorrocks May 28, 2010 07:57

You are using Fluent. Try the Fluent forum.

Archana February 8, 2011 01:20

butterfly valve vane movement
 
I am using solid works flow efd..
I have trouble in moving the vane to various location..
how do we calculate the CV torque and other values for butterfly valve any information would be of great help

ghorrocks February 8, 2011 06:15

What is flow efd? Sounds like you are on the wrong forum too.

Archana February 8, 2011 08:25

Butterfly Valve
 
its flow simulation..
its an add on in solid works.
Which is used for simulation ...
A detatiled "How to do CFD analysis in a butterfly valve ?" is what i am looking for..
It would be kind of you if you could help me...
Thanks and regards
Archana

ghorrocks February 8, 2011 18:22

In that case you definitely have the wrong forum. This forum discusses CFX. Try the general CFD forum.

andro February 24, 2011 15:03

Hi, I use a solid immersed to simulate a butterfly valve, and I He obtains good results, however I have a doubt why that seems to be immersed solid permeable (part of the fluid is able to pass through it)?

ghorrocks February 24, 2011 20:07

Immersed solids work by using a momentum source. You will need to adjust the momentum source scaling factor to stop the flow going through the solid.

Archana February 25, 2011 00:16

IS immeresed solid another software ? what are the steps involved in doing a cfd analysis in a butterfly valve

ghorrocks February 25, 2011 06:40

No, immersed solids is part of CFX. There is a tutorial example of how to use it.


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