CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > CFX

simulation of VIV for a cylinder

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Display Modes
Old   April 13, 2014, 04:45
Default simulation of VIV for a cylinder
  #1
Mal
New Member
 
Ma.L
Join Date: May 2013
Location: ShangHai,China
Posts: 17
Rep Power: 4
Mal is on a distinguished road
i want to simulate a VIV of a cylinder.when water pass through a cylinder,the cylinder will vibrate,so i would like to simulate this phenomenon with CFX by the method of FSI,i Look forward to cylindrical can shake up in the CFD-post. but i don't know how to make it,could you help me? thanks!
Mal is offline   Reply With Quote

Old   April 13, 2014, 06:34
Default
  #2
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 10,949
Rep Power: 85
ghorrocks has a spectacular aura aboutghorrocks has a spectacular aura aboutghorrocks has a spectacular aura about
FIrst of all - try to minimise the use of acronyms. It just makes it hard to read. For the record, VIV = vortex induced vibration, doesn't it?

There are two methods to model this - entirely within CFX using the rigid body solver or coupled with ANSYS FEA.

See the buoy example for an example of the rigid body solver approach. This approach is cimpler and nice, but cannot handle complex constraints.

The ANSYS FEA approach can model just about anything but is more complex and slower.

I cannot judge which approach is better with the information you have provided so far. You would need to describe what is holding the cylinder.
ghorrocks is offline   Reply With Quote

Old   April 14, 2014, 13:27
Default
  #3
Senior Member
 
ok
Join Date: Oct 2013
Posts: 258
Rep Power: 4
Maimouna is on a distinguished road
Dear Mal,

these days, I'm looking exactly to the same case. I'm studying wingMotion in pimpleDyMFoam solver as a test case. The three directories in the wingMotion case are for (i) meshing -snappyHexMesh, (ii) steady solve initialisation - simple, (iii) the moving mesh transient solve -pimpleDyM. I'm still working to get the result. If you get any idea let help each other to reach the result.

All the best.
Maimouna is offline   Reply With Quote

Old   April 14, 2014, 13:29
Default
  #4
Senior Member
 
ok
Join Date: Oct 2013
Posts: 258
Rep Power: 4
Maimouna is on a distinguished road
Dear Glenn,

VIV =Vortex Induced Vibrations.

Regards
Maimouna is offline   Reply With Quote

Old   April 18, 2014, 22:01
Default
  #5
Mal
New Member
 
Ma.L
Join Date: May 2013
Location: ShangHai,China
Posts: 17
Rep Power: 4
Mal is on a distinguished road
Quote:
Originally Posted by Maimouna View Post
Dear Mal,

these days, I'm looking exactly to the same case. I'm studying wingMotion in pimpleDyMFoam solver as a test case. The three directories in the wingMotion case are for (i) meshing -snappyHexMesh, (ii) steady solve initialisation - simple, (iii) the moving mesh transient solve -pimpleDyM. I'm still working to get the result. If you get any idea let help each other to reach the result.

All the best.
Dear Maimouna,
I have found a method of fluid-structure interaction to solve this problem.u can use CFX together with transient structure in workbench.Structure setting is conducted in the transient structure, and u should name a domain interface used to transfer data,then u can write a "inp" file.Flow setting is conducted in the CFX,choose ANSYS MultiField in the external solver coupling,and then inport the "inp"file.The solving way should be the coupling solution in the solution control.
Mal is offline   Reply With Quote

Old   April 18, 2014, 22:16
Default
  #6
Mal
New Member
 
Ma.L
Join Date: May 2013
Location: ShangHai,China
Posts: 17
Rep Power: 4
Mal is on a distinguished road
Quote:
Originally Posted by ghorrocks View Post
FIrst of all - try to minimise the use of acronyms. It just makes it hard to read. For the record, VIV = vortex induced vibration, doesn't it?

There are two methods to model this - entirely within CFX using the rigid body solver or coupled with ANSYS FEA.

See the buoy example for an example of the rigid body solver approach. This approach is cimpler and nice, but cannot handle complex constraints.

The ANSYS FEA approach can model just about anything but is more complex and slower.

I cannot judge which approach is better with the information you have provided so far. You would need to describe what is holding the cylinder.
Dear ghorrocks,
Thanks for you reply, you are right. VIV = vortex induced vibration.i have used the method of coupled with ANSYS FEA to solve my case.The cylinder is holded by a mechanical spring.Could you tell me what is meaning of the calculation curve in the solving procedure, including RMS and volecity and so on.I monitor the displacement of meshing and the force on cylinder in
calculation workspace ,but there are no units of them,so i just don't understand what these Numbers mean. Thank you again.
Mal is offline   Reply With Quote

Old   April 19, 2014, 05:13
Default
  #7
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 10,949
Rep Power: 85
ghorrocks has a spectacular aura aboutghorrocks has a spectacular aura aboutghorrocks has a spectacular aura about
I do not know what you mean by calculation curve.

You seem to be asking about the basics of CFX. You should read the documentation and do the tutorials.
ghorrocks is offline   Reply With Quote

Old   April 21, 2014, 09:41
Default
  #8
Senior Member
 
Join Date: Apr 2009
Posts: 516
Rep Power: 12
stumpy is on a distinguished road
Monitor data is always shown in "Solution Units". These are shown and can be changed in CFX-Pre. They are SI units by default.
stumpy is offline   Reply With Quote

Old   April 21, 2014, 10:25
Default
  #9
Senior Member
 
ok
Join Date: Oct 2013
Posts: 258
Rep Power: 4
Maimouna is on a distinguished road
Dear Maimouna,
I have found a method of fluid-structure interaction to solve this problem.u can use CFX together with transient structure in workbench.Structure setting is conducted in the transient structure, and u should name a domain interface used to transfer data,then u can write a "inp" file.Flow setting is conducted in the CFX,choose ANSYS MultiField in the external solver coupling,and then inport the "inp"file.The solving way should be the coupling solution in the solution control. Dear Mal,

many thanks for your reply. I have some questions please

1. What do you mean by using CFX together with transient structure in workbench?

2. What is ''inp'' file?

3. If I didn't have any experience in ANSYS, how can I do it?

Kind regards

Maimouna
Maimouna is offline   Reply With Quote

Old   April 27, 2014, 02:44
Default
  #10
Mal
New Member
 
Ma.L
Join Date: May 2013
Location: ShangHai,China
Posts: 17
Rep Power: 4
Mal is on a distinguished road
Quote:
Originally Posted by Maimouna View Post
Dear Maimouna,
I have found a method of fluid-structure interaction to solve this problem.u can use CFX together with transient structure in workbench.Structure setting is conducted in the transient structure, and u should name a domain interface used to transfer data,then u can write a "inp" file.Flow setting is conducted in the CFX,choose ANSYS MultiField in the external solver coupling,and then inport the "inp"file.The solving way should be the coupling solution in the solution control.

Dear Mal,

many thanks for your reply. I have some questions please

1. What do you mean by using CFX together with transient structure in workbench?

2. What is ''inp'' file?

3. If I didn't have any experience in ANSYS, how can I do it?

Kind regards

Maimouna
Dear Maimouna,
1.if you want to do some FSI case,you will use the CFX together with transient structure. CFX is for fluid calculation,and transient structure is for structure calculation.
2.The "inp"file is written in transient structure,when you do a FSI case,you should insert this file in CFX as you set the analysis type in CFX-pre.
3.Transient structure is not difficult for you,i think.You just set some boundary conditions and interface in it.For more help,you could look for some tutorials for transient structure.
Kind regards
Mal is offline   Reply With Quote

Old   April 28, 2014, 06:05
Default
  #11
Senior Member
 
ok
Join Date: Oct 2013
Posts: 258
Rep Power: 4
Maimouna is on a distinguished road
Dear Mal,

many thanks for your answers.

Kind regards
Maimouna is offline   Reply With Quote

Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Non stationary simulation of a 2D cylinder lovecraft22 OpenFOAM 8 May 8, 2012 02:06
Cylinder moving simulation with fine/hexe210_2 sirzhyl NUMECA 0 April 9, 2012 09:24
Specifying boundary faces failes in blockMesh blaise OpenFOAM Meshing & Mesh Conversion 0 May 10, 2010 03:56
modification for rotating cylinder simulation zonexo Main CFD Forum 3 July 21, 2006 14:24
Simulation of the Flow past a circular cylinder using STAR-CD M. S. GUEROUACHE Main CFD Forum 0 October 1, 1998 10:51


All times are GMT -4. The time now is 20:42.