|
[Sponsors] |
UDF to input initial value of velocity throughout the domain. |
|
LinkBack | Thread Tools | Search this Thread | Display Modes |
March 1, 2013, 06:53 |
UDF to input initial value of velocity throughout the domain.
|
#1 |
New Member
Delhi
Join Date: Mar 2013
Posts: 2
Rep Power: 0 |
I have to model a lid driven cavity flow where there is initial value of velocity throughout the domain given by some function.
I know how to write UDF for defining boundary condition of velocity, but I am completely clueless as to how write UDF to define initial velocity profile throughout the domain. |
|
March 2, 2013, 05:12 |
|
#2 |
Senior Member
SSL
Join Date: Oct 2012
Posts: 226
Rep Power: 15 |
You can use "DEFINE_INIT".
|
|
March 2, 2013, 06:01 |
|
#3 |
New Member
Delhi
Join Date: Mar 2013
Posts: 2
Rep Power: 0 |
thank you for your reply..
I have one question as after hooking, when is the "DEFINE_INIT" called... Do I have to do standard initialization which I generally do as x vel =0 , y vel = 0 etc and as the solver runs it will then call my UDF to initialize. or I do not have to do the standard/hybrid initialization rather click on something else to initialize the flow using my UDF. |
|
March 2, 2013, 06:19 |
|
#4 |
Senior Member
SSL
Join Date: Oct 2012
Posts: 226
Rep Power: 15 |
Don't worry about it. DEFINE_INIT is on the top of manual initialization and the UDF is preferable to manual initialization.
|
|
October 17, 2013, 14:01 |
UDF interpretation
|
#5 |
New Member
Sagar
Join Date: Oct 2013
Posts: 1
Rep Power: 0 |
Hi guys,
I'm in a spot of bother here. I am trying to do my term project using fluent and I have to simulate the Taylor-Green vortex for Re = 100, with periodic boundary conditions in a cell of unit dimensions (1m x 1m). I want to define the initial velocity of the vortex U = -cos(2*pi*x)sin(2*pi*y) V = sin(2*pi*x)cos(2*pi*y) P = -(cos(4*pi*x) + cos(4*pi*y))/4 I want to enter a .cpp code in the form of a user defined function but I don't know exactly how to do that (I am not aware about the exact syntax to be used). Can anyone please guide me in creating such a code (in a simple way)? Also guide me to feed this program into fluent so that it gets "interpreted" properly. Thanking you in advance. |
|
October 20, 2013, 18:27 |
UDF help
|
#6 |
Member
muhamed
Join Date: Jun 2013
Posts: 66
Rep Power: 13 |
Hello msaeedsadeghi
Could you please help me? I did a simulation of a geometry same as shown in the following movie: https://www.youtube.com/watch?v=e7kiLTy1URU I tried to do the motion same as in the movie, but I couldn't. After I searched in the internet, I noticed that I have to use a UDF to do the motion same as shown in the movie. Please, do you have a tutorial showing how to write a UDF file? I hope you can help me. My email is: mas20001920@yahoo.com Regards.. |
|
October 22, 2013, 15:04 |
Define INIT
|
#7 | |
New Member
A
Join Date: Nov 2012
Location: France
Posts: 7
Rep Power: 14 |
Quote:
A UDF (with DEFINE_INIT) allows initilisation of a sub domain's thread VOF value. This is seen in display-contour-vof. Next, when a calculation is run with this value, even for a single time step, the value of VOF reverts back to its default value in the solution initialisation box. Am I missing something somewhere? What I am trying to do is, in a way an external patch using a UDF.. which seems to fail..when compared to a simple internal patch provided by Fluent. Any ideas? Thanks in advance! Best, A.B. |
||
Tags |
fluent, fluent - udf, udf |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
why divergence occures in these cases | immortality | OpenFOAM Running, Solving & CFD | 2 | January 25, 2013 11:21 |
pisoFoam with k-epsilon turb blows up - Some questions | Heroic | OpenFOAM Running, Solving & CFD | 26 | December 17, 2012 04:34 |
Upgraded from Karmic Koala 9.10 to Lucid Lynx10.04.3 | bookie56 | OpenFOAM Installation | 8 | August 13, 2011 05:03 |
lift and drag on ship superstructures | vaina74 | OpenFOAM Running, Solving & CFD | 3 | June 8, 2010 13:30 |
Computational time | sunnysun | OpenFOAM Running, Solving & CFD | 5 | March 16, 2009 04:32 |