CFD Online URL
[Sponsors]
Home > Forums > FLUENT

Transient Parameter Variation

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

Reply
 
LinkBack Thread Tools Display Modes
Old   April 21, 2010, 16:31
Default Transient Parameter Variation
  #1
New Member
 
Ryan
Join Date: Apr 2010
Posts: 2
Rep Power: 0
Milanowski is on a distinguished road
I'm modeling an airfoil in ANSYS 12.0. I'd like to be able to show the flow responses while changing the angle of attack during flight. What is the best way to do this? I have the angle of attack defined as a parameter in the model.

I've tried defining events in the transient analysis, but I could not come up with a text command to vary a model parameter.

Thank you for your help!
Milanowski is offline   Reply With Quote

Old   April 22, 2010, 09:45
Default
  #2
Senior Member
 
Join Date: Nov 2009
Posts: 411
Rep Power: 10
DoHander is on a distinguished road
You can do a simulation for 0 degree, use this as initial condition for the next angle of attack and so on (you will keep the same geometry but you will change the speed components to reflect the new angle, also you need to change the vectors for force calculations if you monitor Cl and Cd). For each simulation keep the results.

If you don't explicitly need an unsteady calculation the above will give you what you want.

Do
DoHander is offline   Reply With Quote

Old   April 22, 2010, 09:51
Default
  #3
Senior Member
 
Join Date: Nov 2009
Posts: 411
Rep Power: 10
DoHander is on a distinguished road
If you want to simulate a real life flight, with sudden changes in angle and unsteady flow you can implement an UDF to automatically change the speeds components for you at a given time. Say at t=0 seconds you have 0 degrees, at t=120 seconds you have 2 degrees ... This will take a lot of processor resources and it is pretty complicated to implement, it can be justified only if your airfoil oscillates or has rapid changes in incidence. Otherwise the first suggestion works best.

Do
DoHander is offline   Reply With Quote

Old   April 22, 2010, 13:37
Default
  #4
New Member
 
Ryan
Join Date: Apr 2010
Posts: 2
Rep Power: 0
Milanowski is on a distinguished road
Thanks Do,

I'll give the first scenario a try and see how it turns out. I've been looking into UDF's, but I'm fairly pressed for time and I'm not sure I'll be able to get anything of value working.
Milanowski 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
Best practice for transient simulations? siw CFX 5 October 30, 2010 06:45
compile errors of boundary condition "expDirectionMixed" liying02ts OpenFOAM Bugs 2 February 1, 2010 21:11
transient simulation of a rotating rectangle icesniffer CFX 1 August 8, 2009 08:25
Expert Parameter for compressible transient ioannis CFX 0 November 2, 2005 20:28
difference between false and true transient mahesh prakash Main CFD Forum 1 January 21, 1999 14:45


All times are GMT -4. The time now is 21:49.