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Search took 0.00 seconds. Search: Posts Made By: Tobard
Forum: FLUENT May 19, 2011, 17:11
Replies: 37
Views: 20,536
Posted By Tobard
Yes, that was my initial try. And that's because...

Yes, that was my initial try. And that's because it didn't work that I decided to use DEFINE_CG_MOTION... (Yeah, not really logical process order, I know...). So I have encountered the same problem...
Forum: FLUENT May 19, 2011, 15:31
Replies: 37
Views: 20,536
Posted By Tobard
Dear Amir, Everything is already...

Dear Amir,

Everything is already stationary... Does it work for you? I don't see what is wrong... :(
Forum: FLUENT May 18, 2011, 15:46
Replies: 37
Views: 20,536
Posted By Tobard
Hi, I tried this and this is all right....

Hi,

I tried this and this is all right. Points on the boundary are the only ones that have a correct velocity at each time step... That's why it seems really weird to have an inaccurate velocity...
Forum: FLUENT May 17, 2011, 16:50
Replies: 37
Views: 20,536
Posted By Tobard
Hi! It is a very basic UDF: ...

Hi!

It is a very basic UDF:
------------------------------
#include "udf.h"
DEFINE_CG_MOTION(rot_cg, dt, velocity, omega, time, dtime)
{
if(time < 2){
omega[2]=75*time;
}
Forum: FLUENT May 16, 2011, 17:29
Replies: 37
Views: 20,536
Posted By Tobard
Hi, The angular velocity is constant after 2...

Hi,

The angular velocity is constant after 2 seconds.
The problem is that even if I wait for more timesteps this profile doesn't change any more, which is physically impossible. I could have sent...
Forum: FLUENT May 16, 2011, 13:44
Replies: 37
Views: 20,536
Posted By Tobard
Hi Amir, Thank you for this advice, I've...

Hi Amir,

Thank you for this advice, I've checked: my dynamic zones are OK.

To be more precise about my problem, please find attached a picture of the velocity distribution I got.
The flow is...
Forum: FLUENT May 16, 2011, 11:19
Replies: 37
Views: 20,536
Posted By Tobard
Dear Amir, Sorry for coming to you again......

Dear Amir,

Sorry for coming to you again...
My simulations with Dynamic mesh give me strange results. Do you know how Fluent manage the transition between two time steps? The velocity is well...
Forum: FLUENT May 5, 2011, 19:03
Replies: 37
Views: 20,536
Posted By Tobard
Dear Amir, What a relief to receive your...

Dear Amir,

What a relief to receive your answer! It greatly helped me and my problem is solved: it rotates!

I sincerely thank you!

Tobard
Forum: FLUENT May 3, 2011, 14:41
Replies: 37
Views: 20,536
Posted By Tobard
Dear Amir, Do you know where I could find...

Dear Amir,

Do you know where I could find samples or UDF functions close to my problem? I really don't see how to write (and hook) a UDF making my walls move and it is really difficult to find any...
Forum: FLUENT April 14, 2011, 15:42
Replies: 37
Views: 20,536
Posted By Tobard
I work on Fluent 12.0.1 or 12.1 and it seems not...

I work on Fluent 12.0.1 or 12.1 and it seems not to be better. Do you think a moving mesh could be a solution? My geometry is similar to a disk split into to parts...

Tobard
Forum: FLUENT April 13, 2011, 15:10
Replies: 37
Views: 20,536
Posted By Tobard
Hi everybody! I come here again because I...

Hi everybody!

I come here again because I encountered some new difficulties: I succeed in putting a profile law making the wall of my 2D cylinder rotate.

Now I would like to improve my model...
Forum: FLUENT April 4, 2011, 10:22
Replies: 37
Views: 20,536
Posted By Tobard
Hi, I post this last message to thank you:...

Hi,

I post this last message to thank you: my simulation is now working, using DEFINE_PROFILE just as you said.
A little feedback: working with direct coordinates rather than using...
Forum: FLUENT March 30, 2011, 17:19
Replies: 37
Views: 20,536
Posted By Tobard
Thank you, it helps me much! I just would like to...

Thank you, it helps me much! I just would like to understand some points:

- My study needs to change ONLY wall (boundary) velocity (and then observe inertia and viscosity action into the fluid)....
Forum: FLUENT March 30, 2011, 12:20
Replies: 37
Views: 20,536
Posted By Tobard
Hi, Following your advice and trying to...

Hi,

Following your advice and trying to understand UDF philosophy, I have written the following function (I think I will have to do 2 different files in order to fill both X and Y velocity...
Forum: FLUENT March 29, 2011, 11:15
Replies: 37
Views: 20,536
Posted By Tobard
Dear Amir, Ok, I am trying to use these UDF....

Dear Amir,

Ok, I am trying to use these UDF. Since I am not really used to this option, it is difficult for me to understand how to implement coordinates of surface elements, as you said. Would it...
Forum: FLUENT March 28, 2011, 13:44
Replies: 37
Views: 20,536
Posted By Tobard
Thank you for your answer. I tried this but I...

Thank you for your answer. I tried this but I would like to input a rotational speed and the only velocity components that are displayed are X, Y and Z components in m/s... Is it possible to change...
Forum: FLUENT March 28, 2011, 12:53
Replies: 37
Views: 20,536
Posted By Tobard
Moving wall with velocity profile

Hi everyone!

I need to study a transient flow inside a closed cylinder which is starting to rotate. It seems impossible to put a velocity profile instead of a constant value under rotating wall...
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