|
[Sponsors] |
![]() |
![]() |
#1 |
New Member
Leonardo Armas
Join Date: Apr 2012
Posts: 2
Rep Power: 0 ![]() |
Hello World!
I have been working in the past few days trying to understand UDFs but i think i've reached a dead end... This is what i'm trying to do: I'm just trying to simulate the flow around a body wich is moving up and down with a sinusoidal law of motion. To do this i have written my UDF just as is shown below: #include "udf.h" DEFINE_CG_MOTION(object_mov, dt, vel, omega, time, dtime) { real a, w, pi; pi = 3.1415; /* define motion variables */ a = 0.05; /* 0.05m movement amplitude */ w = 2 * pi * 2; /* 2Hz frequency */ /* define object movement law */ vel[0] = 0; vel[1] = -a * w * sin(w*time); vel[2] = 0; } I have no problem interpreting this UDF into Fluent. However, when defining the dynamic zone the following warning appears: "Warning: incorrect cg motion UDF wing on zone 4 (assuming no motion)" Do you have any clue why could this be? is my UDF correctly written? Looking forward to your answer. Thanks! |
|
![]() |
![]() |
![]() |
![]() |
#2 |
New Member
Leonardo Armas
Join Date: Apr 2012
Posts: 2
Rep Power: 0 ![]() |
Just to say that I have solved the problem: CG motion macro only works when compiled!!
|
|
![]() |
![]() |
![]() |
![]() |
#3 |
New Member
Jessica Simberg
Join Date: Mar 2012
Posts: 18
Rep Power: 13 ![]() |
Hi,
your missing a math header, try using these: #include "udf.h" #include "stdio.h" #include "stdlib.h" #include "math.h" #include "dynamesh_tools.h" #include "storage.h" In addition, define an intermediate (i.e. "real v = 0") variable for the motion: v = -a * w * sin(w*time); vel[1] = v; hopefully it will solve your problem... |
|
![]() |
![]() |
![]() |
![]() |
#4 |
New Member
Hossein
Join Date: Jul 2012
Posts: 2
Rep Power: 0 ![]() |
||
![]() |
![]() |
![]() |
![]() |
#5 |
New Member
roham lavimi
Join Date: Apr 2015
Posts: 1
Rep Power: 0 ![]() |
I cant write udf code for flapping motion in hover, help me, im so confused
|
|
![]() |
![]() |
![]() |
![]() |
#6 |
New Member
Jessica Simberg
Join Date: Mar 2012
Posts: 18
Rep Power: 13 ![]() |
do it with solidworks flow simulation.
J |
|
![]() |
![]() |
![]() |
![]() |
#7 |
New Member
Manahara Manatunga
Join Date: Mar 2014
Posts: 15
Rep Power: 11 ![]() |
||
![]() |
![]() |
![]() |
![]() |
#8 | |
New Member
mortezasekaloo
Join Date: Apr 2016
Posts: 4
Rep Power: 8 ![]() |
Quote:
I am the student of fluid mechanics and now I am studying on fluid project. The subject of my project is about blade turbine that Oil radially impacts to the turbine blades by a nozzle, causing the turbine to spin. I have a problem in modeling of turbine that I don’t know how to obtain moment of inertia of blade and fluid and how to relate this challenge to the Cg motion until I can model this turbine in fluent software. Please help me Thank for your attention |
||
![]() |
![]() |
![]() |
![]() |
#9 |
Senior Member
Arun raj.S
Join Date: Jul 2011
Posts: 190
Rep Power: 13 ![]() |
Hi everyone,
I am simulating flapping wing of aerofoil. I have created three zones, zone 1, 2 and 3. Zone 1 has aerofoil with structured mesh around the aerofoil. Zone 2 and 3 has unstructured gird. My problem is I have properly followed all the steps. But I am not able to achieve what I want. Because the shadow of the interface is taking as wall and is not moving along with the domain. Kindly someone help in sorting out this issue. I have attached my UDF alos. Please have a look. Thank you so much https://drive.google.com/file/d/0B7L...ew?usp=sharing https://drive.google.com/file/d/0B7L...ew?usp=sharing |
|
![]() |
![]() |
![]() |
![]() |
#10 |
New Member
Rubel Ahammed
Join Date: May 2019
Posts: 13
Rep Power: 5 ![]() |
Dear Experts,
I am trying to do a moving mesh for a body which is moving up and down. To do this I have written below UDF: #include "udf.h" static real velx = 0.0; DEFINE_CG_MOTION(box,dt,vel,omega,time,dtime) { NV_S(vel, =, 0.0); NV_S(omega, =, 0.0); velx = 0.05 * sin(3.1415927 * time / 10.); Message ("time = %f, vel[0] =%f\n", time, vel[0]); } during compile i have face below error mentioned below: Error: The UDF library you are trying to load (D:\MR Damper\CG Motion\Moving Mesh_files\dp0\FFF\Fluent\libudf) is not compiled for 2d on the current platform (win64). The system cannot find the file specified. D:\MR Damper\CG Motion\Moving Mesh_files\dp0\FFF\Fluent\D:\MR Damper\CG Motion\Moving Mesh_files\dp0\FFF\Fluent\libudf\win64\2d\libudf.d ll How can I solve this problem? looking forward to your answer. Thanks |
|
![]() |
![]() |
![]() |
![]() |
#11 |
New Member
Jessica Simberg
Join Date: Mar 2012
Posts: 18
Rep Power: 13 ![]() |
Honestly, if you can do it in star ccm+
Ansys suck where moving geometries and large displacements are needed... |
|
![]() |
![]() |
![]() |
![]() |
#12 | |
Senior Member
Alexander
Join Date: Apr 2013
Posts: 2,256
Rep Power: 32 ![]() ![]() |
Quote:
best regards |
||
![]() |
![]() |
![]() |
![]() |
#13 |
New Member
Sharif
Join Date: Nov 2019
Posts: 2
Rep Power: 0 ![]() |
train.c
tunnel.c error1.PNG Hello everyone, I'm trying to get my train to move but no matter what I try, I'm not able to compile the files. I'm not sure if its the file having issues or my settings are the problem. I hope someone could shed some light on this for me. Thanks ![]() |
|
![]() |
![]() |
![]() |
![]() |
#14 | |
Senior Member
Alexander
Join Date: Apr 2013
Posts: 2,256
Rep Power: 32 ![]() ![]() |
Quote:
__________________
best regards ****************************** press LIKE if this message was helpful |
||
![]() |
![]() |
![]() |
![]() |
#15 |
New Member
Gyan
Join Date: Dec 2019
Posts: 1
Rep Power: 0 ![]() |
The program is wrong, even I have also stuck with the same problem.
|
|
![]() |
![]() |
![]() |
![]() |
#16 |
New Member
Furkan Enes
Join Date: May 2021
Posts: 3
Rep Power: 3 ![]() |
I also get the same warning with you. However, when I try to compile my UDF, it is said that libudf does not exist. Did you get any error something like this?
|
|
![]() |
![]() |
![]() |
![]() |
#17 |
Senior Member
Alexander
Join Date: Apr 2013
Posts: 2,256
Rep Power: 32 ![]() ![]() |
unload all UDF folders via udf manager,
make any changes in source file you are going to compile compile
__________________
best regards ****************************** press LIKE if this message was helpful |
|
![]() |
![]() |
![]() |
![]() |
#18 |
New Member
Furkan Enes
Join Date: May 2021
Posts: 3
Rep Power: 3 ![]() |
May you help me with my second question in this forum? I am new in this forum and try to get help. I think there are not enough people seeing my post. I don't know why.
Thank you so much |
|
![]() |
![]() |
![]() |
Tags |
udf cg motion |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Thread Starter | Forum | Replies | Last Post |
ATTN ALL: SOLUTON TO UDF COMPILE PROBLEM | Rizwan | Fluent UDF and Scheme Programming | 40 | March 18, 2018 06:05 |
Moving mesh | Niklas Wikstrom (Wikstrom) | OpenFOAM Running, Solving & CFD | 122 | June 15, 2014 06:20 |
udf compiling problem | akr | FLUENT | 3 | August 22, 2007 07:14 |
UDF PROBLEM | anant | FLUENT | 2 | January 17, 2007 00:15 |
UDF error CG Motion | Alex | FLUENT | 0 | March 22, 2006 17:40 |