# UDF starter

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

 July 16, 2012, 03:36 UDF starter #1 New Member   Vignesh V Join Date: Jun 2012 Posts: 16 Rep Power: 6 Hi, I'm trying to write my own UDF. I'm not getting anything from the FLUENT user guide. Someone please help me with some example. How could i proceed in writing my own UDF.

 July 16, 2012, 06:22 #2 Senior Member     Alex Join Date: Jun 2012 Location: Germany Posts: 1,433 Rep Power: 23 Tell us what you want to achieve with the UDF. Then we can be a little more specific with the guidance we provide.

 July 16, 2012, 08:42 Udf #3 New Member   Vignesh V Join Date: Jun 2012 Posts: 16 Rep Power: 6 Hi, I'm new to UDF. I'm trying to simulate a moving wall over a fluid. Can u help me.

 July 16, 2012, 08:56 #4 Senior Member     Alex Join Date: Jun 2012 Location: Germany Posts: 1,433 Rep Power: 23 The possibilities with UDFs are nearly infinite. So is the range of complexity of UDFs. Before you start writing a UDF, you should know what it is supposed to do.

 July 16, 2012, 12:25 New question of dynamic mesh-udf #5 New Member   Join Date: Jul 2012 Posts: 1 Rep Power: 0 HELLO i want to use dynamic mesh to simulate a motion of a microorganism.i have understood that i have to write a UDF to define a motion of microorganism for fluent.i have 6 pictures(including data of positions) of microorganism in one cycle of its swimming motion.now these are my questions: 1- what my program suppose to do?(i am actually a little confused about it) 2- Do i have to interpolate to find the position of nodes through the time? 3-Do i need to calculate the velocity and acceleration of nodes too?(i only have data for positions) 4-which marcos should i use? i have read the UDF manual but i didnt get whole of it.I would be thankful for any help from you?

 July 17, 2012, 01:02 Udf #6 New Member   Vignesh V Join Date: Jun 2012 Posts: 16 Rep Power: 6 Let us take an example of landing of aircraft(from certain height till its completely lands). Is it need to define a UDF . If yes how to start. I tell you again I'm new to UDF. So, It would be helpful if you help in some basics steps how to write a UDF.

 July 17, 2012, 02:27 #7 Senior Member     Alex Join Date: Jun 2012 Location: Germany Posts: 1,433 Rep Power: 23 I feel like we are speaking different languages here. The landing of an aircraft provides about a trillion possibilities for the use of UDFs. Since the setup of the simulation is not even defined, I could only guess what the application of a UDF in this context could be. The range is from setting a time-variant density ot the fluid to defining the movement of the landing flaps. I am very sorry, but I can't provide any guidance about a topic that is totally vague.

 July 17, 2012, 05:36 Udf #8 New Member   Vignesh V Join Date: Jun 2012 Posts: 16 Rep Power: 6 Hi, Just tell me how to write a time dependent B.C's using UDF. The problem is like flow of a water in a tank.

 August 4, 2012, 05:17 udf #9 Senior Member   Vaze Join Date: Jun 2009 Posts: 153 Rep Power: 9 Hi Vignesh Read DEFINE_PROFILE macro. One UDF for already written for spatial variation of velocity for the flow over aerofoil. In this profile make some modifications like - first call and specify the real time as time variable 't' and change the equation of your kind with time variable 't'. best wishes Mvee

 Thread Tools Display Modes Linear Mode

 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 OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post Qureshi FLUENT 7 March 23, 2017 08:37 pchoopanya Fluent UDF and Scheme Programming 1 August 28, 2013 06:12 shankara.2 Fluent UDF and Scheme Programming 1 January 16, 2012 23:14 kim FLUENT 3 October 26, 2011 21:38 Luc SEMINEL Main CFD Forum 0 November 25, 2002 05:01

All times are GMT -4. The time now is 23:25.