CFD Online Logo CFD Online URL
Home > Forums > FLUENT

UDF to make a flap move

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

LinkBack Thread Tools Display Modes
Old   October 8, 2010, 06:03
Default UDF to make a flap move
New Member
Join Date: Jul 2010
Posts: 25
Rep Power: 9
bramdiff is on a distinguished road
Dear all

I am new to fluent, and am currently learning the tutorials etc, and have a question regarding how exactly a udf works, and how i could use them. As part of my phd research, i am working on a vertical axis turbine, but the fluid is allowed to move the flaps (or blades) i.e consider it a rigid plate that is pin jointed at one end. Depending on the position of the flap the fluid will hit it, and rotate it, and this is what i need to model. (also analogous to model a door being blown by the wind I want to know how much it would move)

Many people have advised me that a udf is needed, the pressure on either side of the flap can be calculated and thus a resultant force. this can be then linked to a rotation on the flap.

this is great but I still have a couple of questions...

in terms of relating the movement would you use simply the relationship of centripetal force to angular velocity, ie F=m*r*Omega^2??? if this was the case would the udf calculate the resultant force, and return the angular velocity of the flap, would fluent then automatically give the flap this angular velocity and therefore move it?

also does a udf perform its calculation once every timestep, or for every iteration, or can you set that??

If someone could breifly explain what fluent does, and if you think the above solution strategy is valid/invalid, please feel free to comment

If anyone has any other suggestions or ideas of how this can be done im all ears, your help is appreciated!!

Many thanks

bramdiff is offline   Reply With Quote


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
Help! Compiled UDF problem 4 Wave tank tutorial Shane FLUENT 1 September 3, 2010 02:32
UDF or Sliding Mesh? Chris FLUENT 1 April 22, 2008 10:43
OpenFOAM with IBM AIX matthias OpenFOAM Installation 20 March 25, 2008 03:36
Compiling OpenFOAM13 on AMD64 with OpenSUSE 101 silent_missile OpenFOAM Installation 5 August 10, 2007 07:31
a way to make lots of money quick and easy no lies Dob Main CFD Forum 0 October 10, 2006 16:45

All times are GMT -4. The time now is 00:14.