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

Fluid structure interaction in ANSYS-CFX

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   February 12, 2011, 16:00
Question Fluid structure interaction in ANSYS-CFX
  #1
New Member
 
Amol
Join Date: Feb 2011
Posts: 4
Rep Power: 15
Amol is on a distinguished road
Hello everybody,
i am doing flutter analysis with two way FSI, coupling ANSYS(transient analysis system) and CFX. structural domain is panel of 5 mm thickness and fluid has supersonic flow above it. now problem is that when i am keeping large deflection ON in mechanical part of the ANSYS (i.e. by doing this i am considering geometric non linearity in panel) panel shows nice limit cycle oscillations in it (of amplitude 0.004 m without giving any initial disturbance to panel). but when i am doing same simulation with keeping large deflection OFF (i.e. geometric nonlinearity removed) it should show large deflections in panel instead of limit cycle oscillations. but don't know why i am getting very small deflections in panel (amplitude of just some nanometer). what might be going wrong?? please help................
Amol is offline   Reply With Quote

Old   February 22, 2011, 12:52
Default
  #2
New Member
 
Ji Pei
Join Date: Nov 2010
Posts: 8
Rep Power: 16
peiji1984 is on a distinguished road
I have the same question! I did a FSI calculation for a water pump impeller, and it seems to be linear problem(0.1-0.5mm deflection according to the test). So I have tried to keep large deflection off, the values are small, like 100 times less than experiment. One way coupling seems right. When I keep large deflection on, the deflection curve is not quite right. It is confusing! So I want to know, what has happened in software when large deflection is off.
peiji1984 is offline   Reply With Quote

Old   April 4, 2011, 02:08
Default
  #3
New Member
 
Vahid
Join Date: Jan 2011
Posts: 23
Rep Power: 15
va-ta-cfd is on a distinguished road
Hello
I have the same problem and the structure (a long plate behind a rigid cylinder) has very little cross flow oscillation due to the vortex shedding.
it would be very helpful if any body has got the reason .

thanks
V.T
va-ta-cfd is offline   Reply With Quote

Old   April 4, 2011, 10:49
Default
  #4
Senior Member
 
Edmund Singer P.E.
Join Date: Aug 2010
Location: Minneapolis, MN
Posts: 511
Rep Power: 21
singer1812 is on a distinguished road
Large deflections must be on for 2way FSI. Loads will be always applied to non-deformed body (within Mechanical Ansys) if large deflections are not on.
singer1812 is offline   Reply With Quote

Old   April 4, 2011, 13:18
Default
  #5
New Member
 
Amol
Join Date: Feb 2011
Posts: 4
Rep Power: 15
Amol is on a distinguished road
Quote:
Originally Posted by singer1812 View Post
Large deflections must be on for 2way FSI. Loads will be always applied to non-deformed body (within Mechanical Ansys) if large deflections are not on.
even though the load is applied on non deformed bodies when we keep geometric nonlinearity OFF, what is the reason to get small deformations in structures as compared to the case when we keep geometric nonlinearity ON.
Is there any other option available in mechanical ANSYS while doing 2 way FSI using ANSYS-CFX????
Amol is offline   Reply With Quote

Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Fluid Structure Interaction using MFX : ANSYS-CFX Manoj Kumar CFX 2 June 3, 2015 08:41
Fluid Structure Interaction using icoFsiFoam Problems lr103476 OpenFOAM Running, Solving & CFD 79 August 7, 2014 10:30
Fluid Structure Interaction Apollo Main CFD Forum 5 July 4, 2011 17:15
Fluid Structure Interaction pk Main CFD Forum 6 August 15, 2005 17:24
Fluid structure interaction ken Main CFD Forum 0 March 9, 2004 20:10


All times are GMT -4. The time now is 12:54.