CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums

Search Results

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

Showing results 1 to 17 of 17
Search took 0.00 seconds.
Search: Posts Made By: montag dp
Forum: Fluent UDF and Scheme Programming March 8, 2011, 18:35
Replies: 76
Views: 24,008
Posted By montag dp
I just use those same boundary conditions. It...

I just use those same boundary conditions. It seems to work okay. I don't think it's extremely important what you use for the boundaries if there is no inlet velocity.
Forum: Fluent UDF and Scheme Programming February 13, 2011, 22:59
Replies: 76
Views: 24,008
Posted By montag dp
Sounds like the same thing I'm doing then, except...

Sounds like the same thing I'm doing then, except I'm just keeping it to two rotations. I wish you luck. Maybe try going through that pdf I posted on the previous page that someone sent me? I...
Forum: Fluent UDF and Scheme Programming February 13, 2011, 22:51
Replies: 76
Views: 24,008
Posted By montag dp
Sorry, I'm afraid I don't have more time to...

Sorry, I'm afraid I don't have more time to troubleshoot this problem in Fluent. I only have the transformation in a simplified version for 2 rotations (assuming the third is 0). Did you say you...
Forum: Fluent UDF and Scheme Programming February 13, 2011, 22:23
Replies: 76
Views: 24,008
Posted By montag dp
I've been able to do two rotations as well. All...

I've been able to do two rotations as well. All I know about the problem is in my last few posts. The Euler rate transformations seem to work in 2 axes but I haven't tried them in 3.
Forum: Fluent UDF and Scheme Programming February 9, 2011, 12:11
Replies: 76
Views: 24,008
Posted By montag dp
Aamer, if I'm understanding you right, your...

Aamer, if I'm understanding you right, your problem actually has a very simple solution. Since your wing is starting in the wrong orientation, you can just go to Mesh>Rotate and rotate your entire...
Forum: Fluent UDF and Scheme Programming February 8, 2011, 12:45
Replies: 76
Views: 24,008
Posted By montag dp
Aamer, To do a simple wing sweep depends on...

Aamer,

To do a simple wing sweep depends on how exactly you want to do the sweep. If it will be a constant speed, I believe you can use a moving mesh or rotating reference frame approach, but I...
Forum: Fluent UDF and Scheme Programming February 6, 2011, 13:03
Replies: 76
Views: 24,008
Posted By montag dp
Sorry aamer, that pdf was given to me by Jakub K,...

Sorry aamer, that pdf was given to me by Jakub K, as I said in the post. I don't have the book.
Forum: Fluent UDF and Scheme Programming February 1, 2011, 14:15
Replies: 76
Views: 24,008
Posted By montag dp
Actually, here's something that someone sent me. ...

Actually, here's something that someone sent me. This guy did a flapping simulation of a dragonfly in fluent, which you should be able to find easily on youtube. I asked him how he did his...
Forum: Fluent UDF and Scheme Programming February 1, 2011, 13:41
Replies: 76
Views: 24,008
Posted By montag dp
It certainly seems like it would be simplest if...

It certainly seems like it would be simplest if they just used a global coordinate system for the rotation, but it seems they have it defined based on the local body axes, which change orientation...
Forum: Fluent UDF and Scheme Programming February 1, 2011, 13:24
Replies: 76
Views: 24,008
Posted By montag dp
Dave, In the end I was able to get rotations...

Dave,

In the end I was able to get rotations in two axes to work as follows.

Nomenclature:
Phi: flapping angle (about global Z-axis)
theta: pitching angle (about global X-axis)
...
Forum: Fluent UDF and Scheme Programming August 3, 2010, 16:24
Replies: 76
Views: 24,008
Posted By montag dp
For reference, here is a copy of my code. The...

For reference, here is a copy of my code. The first would define flapping + pitching motion, assuming the rotations are defined relative to the stationary axes:

#include "udf.h"
...
Forum: Fluent UDF and Scheme Programming August 3, 2010, 12:05
Replies: 76
Views: 24,008
Posted By montag dp
Ok, now really confused

I thought I had this right, but now I'm just more confused. I'm trying to just get motion about the x and y axes. I thought the Euler rate equations would help do this, but then I realized I'm...
Forum: Fluent UDF and Scheme Programming August 3, 2010, 09:36
Replies: 76
Views: 24,008
Posted By montag dp
Almostafa, First off, it looks like you...

Almostafa,

First off, it looks like you could simplify your code down to just:

# include "udf.h"
# include "dynamesh_tools.h"
DEFINE_CG_MOTION(pump,dt,vel,omega,time,dtime)
{
real freq_t;...
Forum: Fluent UDF and Scheme Programming August 2, 2010, 16:14
Replies: 76
Views: 24,008
Posted By montag dp
For posterity, I figured out how to solve my...

For posterity, I figured out how to solve my problem. Use the Euler rate transformations in the UDF in order to convert between body and stationary velocities. You'll also need to use the current...
Forum: Fluent UDF and Scheme Programming July 30, 2010, 12:27
Replies: 76
Views: 24,008
Posted By montag dp
Another question. In the Fluent User's manual it...

Another question. In the Fluent User's manual it says you can check a moving body's center of gravity position and orientation in the dynamic mesh box by pressing 'Update.' See here:
...
Forum: Fluent UDF and Scheme Programming July 30, 2010, 10:45
Replies: 76
Views: 24,008
Posted By montag dp
I haven't had any luck either. I tried doing a...

I haven't had any luck either. I tried doing a coordinate transformation to transform rotations about the reference x, y, and z axes to rotations about the moving body x, y, and z axes. It gets the...
Forum: Fluent UDF and Scheme Programming July 26, 2010, 16:43
Replies: 76
Views: 24,008
Posted By montag dp
CG Motion Absolute coordinates

I'm having a little trouble with the Define_CG_Motion macro. I'm trying to do a simulation of a wing that is both flapping and pitching. The flapping is a rotation about the x-axis and the pitching...
Showing results 1 to 17 of 17

 
Forum Jump

All times are GMT -4. The time now is 11:53.