CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > FLUENT > Fluent UDF and Scheme Programming

3D wing (flapping elastically) flexing UDF problem

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   February 20, 2012, 11:49
Question 3D wing (flapping elastically) flexing UDF problem
  #1
New Member
 
Join Date: Feb 2012
Posts: 4
Rep Power: 14
djan is on a distinguished road
Hello, Im trying to simulate the flexing( flapping up and down elastically) of a wing in 3D. But im having problems with the UDF, its just rotating the wing along the x direction instead of updating the y position based on the position of the z position to flap it down. I'd be very happy if somebody could help me with it. Im attaching a picture showing only the wing to help with axis. The UDF im using is as follows:

#include"udf.h"
DEFINE_GRID_MOTION(wing, domain, dt, time, dtime)
{
Thread *tf = DT_THREAD (dt);
face_t f;
Node *v;
real NV_VEC (axis), dy;
real NV_VEC (origin);

int n;

/* set deforming flag on adjacent cell zone */
SET_DEFORMING_THREAD_FLAG (THREAD_T0 (tf));
 

Message (
"time = %f\n", time);

NV_D (axis, =, 0.0, 0.0, 1.0);
NV_D (origin, =, 0.0, 0.0, 0.0);

begin_f_loop (f, tf)
{
f_node_loop (f, tf, n)
{
v = F_NODE (f, tf, n);
/* update node if z position is greater than 0.000
and that the current node has not been previously
visited when looping through previous faces */
if (NODE_Z (v) > 0.000 && NODE_POS_NEED_UPDATE (v))
{
/* indicate that node position has been update
so that it's not updated more than once */
NODE_POS_UPDATED (v);
dy = (0.0271*pow (NODE_Z (v), 2)) + (0.2496*NODE_Z (v)) + 0.1396;
NODE_Y (v) = NODE_Y (v) + dy;
}
}
}
end_f_loop (f, tf);
}


Attached Images
File Type: jpg Capture.jpg (17.8 KB, 91 views)
djan is offline   Reply With Quote

Old   February 27, 2012, 02:28
Default 3D flapping wing
  #2
hhh
Senior Member
 
kunar
Join Date: Nov 2011
Posts: 117
Rep Power: 15
hhh is on a distinguished road
Dear djan,
i am also trying to do analysis in flapping wing(dragonfly),i draw cad model in catia,and i did mesh in gambit right now i am trying to write udf and compile in fluent ,i dont know how to write, i saw your post i want some help from you i am starting stage only for write udf.kindly guide me
hhh is offline   Reply With Quote

Old   March 16, 2012, 03:37
Default
  #3
Member
 
Join Date: Mar 2011
Posts: 50
Rep Power: 15
cdf_user is on a distinguished road
either something wrong with your equation
or the way you update ur nodes

I think it has something to do with updating the nodes
cdf_user is offline   Reply With Quote

Old   March 30, 2012, 12:37
Default
  #4
New Member
 
irfan khan
Join Date: Aug 2011
Posts: 11
Rep Power: 15
imbaasat is on a distinguished road
function probably seem to be parabolic. for flapping, sinsusoidal is required. moreover time varation be also included.
imbaasat is offline   Reply With Quote

Reply

Tags
3d fluent, dynamic mesh, udf, wing flapping


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 Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
ATTN ALL: SOLUTON TO UDF COMPILE PROBLEM Rizwan Fluent UDF and Scheme Programming 40 March 18, 2018 07:05
Problem with my udf july Fluent UDF and Scheme Programming 3 June 20, 2010 07:56
UDF problem on single computer with two procesor Dmitry FLUENT 3 May 18, 2005 13:44
a problem about DEFINE_GEOM in dynamic mesh UDF speedcat FLUENT 1 May 16, 2005 04:09
I have problem of UDF with turbulent premx source. Z FLUENT 0 February 16, 2005 04:34


All times are GMT -4. The time now is 03:53.