3D Door Swing

rw511 · July 21, 2011, 06:12

Hello all,

I'm looking at modelling a door opening in a room. I started with a 2D (top-down) model, a UDF that opens to 45 degrees and the remeshing was absolutely fine. When I moved onto the problem in 3D, the remeshing is lacklustre at best. From my starting (unstrucutred) mesh with a max cell skew of about 0.75, when I preview the mesh motion, within about 0.001 seconds of flow time (of which I use 10 time steps at 0.0001) the cell skewness often exceeds 0.9 but will come back to around 0.8 and fluctuate around there. The simulation eventually crashes after 0.17 seconds of flow time due to a negative cell volume error. I've played around with the various remeshing and smoothing cettings but to no avail. If anyone has any information on remeshing using angular movements as opposed to the typical linear movements, it would be greatly appreciated.

Rich.

Trev · July 21, 2011, 09:52

Surely it would be easier to use a moving reference frame than use dynamic meshing for your problem.

f.hn319 · March 16, 2021, 02:26

Quote:

Originally Posted by rw511

Hello all,

I'm looking at modelling a door opening in a room. I started with a 2D (top-down) model, a UDF that opens to 45 degrees and the remeshing was absolutely fine. When I moved onto the problem in 3D, the remeshing is lacklustre at best. From my starting (unstrucutred) mesh with a max cell skew of about 0.75, when I preview the mesh motion, within about 0.001 seconds of flow time (of which I use 10 time steps at 0.0001) the cell skewness often exceeds 0.9 but will come back to around 0.8 and fluctuate around there. The simulation eventually crashes after 0.17 seconds of flow time due to a negative cell volume error. I've played around with the various remeshing and smoothing cettings but to no avail. If anyone has any information on remeshing using angular movements as opposed to the typical linear movements, it would be greatly appreciated.

Rich.

hi
i want to model the door open and closing in the room can you help me ? i dont know any thing of that

rw511 · March 16, 2021, 04:34

Hi,

I don't recall the ins and outs of what I did in the end, but I did get the door swinging using dynamic meshing within Fluent. I'm not sure if anything has changed in that area, but at the time I found it difficult to control parameters affecting the mesh.

If I were to do that again, I'd use a rotating reference frame, as Trev mentions, or a rotational sliding mesh that contains the door. Dynamic meshing probably wasn't the correct approach in that instance, even though it did produce reasonable results in my case.

Good luck,
Rich

tahar · March 22, 2021, 09:46

the remeshing technique is bad choise
use moving ZONE or use LAyering techique with the option split based on cell ratio you can simply save a lot of computational time

DEFINE ZONE MOTION and DEFINE CG MOTION CAN BE USED

July 21, 2011, 06:12	3D Door Swing	#1
rw511 New Member Richard Join Date: May 2011 Posts: 10 Rep Power: 14	Hello all, I'm looking at modelling a door opening in a room. I started with a 2D (top-down) model, a UDF that opens to 45 degrees and the remeshing was absolutely fine. When I moved onto the problem in 3D, the remeshing is lacklustre at best. From my starting (unstrucutred) mesh with a max cell skew of about 0.75, when I preview the mesh motion, within about 0.001 seconds of flow time (of which I use 10 time steps at 0.0001) the cell skewness often exceeds 0.9 but will come back to around 0.8 and fluctuate around there. The simulation eventually crashes after 0.17 seconds of flow time due to a negative cell volume error. I've played around with the various remeshing and smoothing cettings but to no avail. If anyone has any information on remeshing using angular movements as opposed to the typical linear movements, it would be greatly appreciated. Rich.

July 21, 2011, 09:52		#2
Trev Member Neil Join Date: Jun 2009 Location: The Moon Posts: 42 Rep Power: 16	Surely it would be easier to use a moving reference frame than use dynamic meshing for your problem.

March 16, 2021, 04:34		#4
rw511 New Member Richard Join Date: May 2011 Posts: 10 Rep Power: 14	Hi, I don't recall the ins and outs of what I did in the end, but I did get the door swinging using dynamic meshing within Fluent. I'm not sure if anything has changed in that area, but at the time I found it difficult to control parameters affecting the mesh. If I were to do that again, I'd use a rotating reference frame, as Trev mentions, or a rotational sliding mesh that contains the door. Dynamic meshing probably wasn't the correct approach in that instance, even though it did produce reasonable results in my case. Good luck, Rich

March 22, 2021, 09:46		#5
tahar New Member moh Join Date: Jan 2014 Posts: 20 Rep Power: 12	the remeshing technique is bad choise use moving ZONE or use LAyering techique with the option split based on cell ratio you can simply save a lot of computational time DEFINE ZONE MOTION and DEFINE CG MOTION CAN BE USED