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-   -   block-structured mesh for t-junction (https://www.cfd-online.com/Forums/ansys-meshing/91929-block-structured-mesh-t-junction.html)

Robert@cfd August 26, 2011 12:10
block-structured mesh for t-junction
 
5 Attachment(s)
Hey forum,

I have to do a block-structured mesh for T-junction. There it would be nice, if you could give me some hints in creating a high quality mesh. I'm adding pics of a first shot.

I'm also having problems in associating correctly, as you can see in the region of blending

greetings, robert

BrolY August 29, 2011 03:36
Can you attach the *.tin file here ?
I could have a look ;)

Robert@cfd August 29, 2011 05:59
Hi

At the moment I can just give you the replay-file, maybe you can test it there.

Code:
ic_geo_new_family GEOM
ic_boco_set_part_color GEOM
ic_empty_tetin
ic_point {} GEOM pnt.00 0,0,0
ic_point {} GEOM pnt.01 0,0,1
ic_point {} GEOM pnt.02 0.027,0,1
ic_point {} GEOM pnt.03 0.027,0,0
ic_point {} GEOM pnt.04 0,0.027,0
ic_point {} GEOM pnt.05 0,0.027,1
ic_point {} GEOM pnt.06 0,0,0.2
ic_point {} GEOM pnt.07 0,0.027,0.2
ic_point {} GEOM pnt.08 0,0,0.227
ic_point {} GEOM pnt.09 0.2,0,0.227
ic_point {} GEOM pnt.10 0.2,0,0.2
ic_point {} GEOM pnt.11 0.2,0.027,0.2
ic_curve arc_ctr_rad GEOM crv.00 {pnt.01 pnt.05 pnt.02 0.027000001 0 360}
ic_curve arc_ctr_rad GEOM crv.01 {pnt.06 pnt.07 pnt.08 0.027000001 0 360}
ic_curve arc_ctr_rad GEOM crv.02 {pnt.10 pnt.11 pnt.09 0.027000001 0 360}
ic_curve arc_ctr_rad GEOM crv.03 {pnt.00 pnt.04 pnt.03 0.027000001 0 360}
ic_geo_new_family OUT
ic_boco_set_part_color OUT
ic_surface 2-4crvs OUT srf.00 {0.01 crv.00}
ic_set_dormant_pickable point 0 {}
ic_set_dormant_pickable curve 0 {}
ic_geo_delete_family TEMP_TSF_FAM
ic_geo_new_family IN1
ic_boco_set_part_color IN1
ic_surface 2-4crvs IN1 srf.01 {0.01 crv.03}
ic_set_dormant_pickable point 0 {}
ic_set_dormant_pickable curve 0 {}
ic_geo_delete_family TEMP_TSF_FAM
ic_geo_new_family IN2
ic_boco_set_part_color IN2
ic_surface 2-4crvs IN2 srf.02 {0.01 crv.02}
ic_set_dormant_pickable point 0 {}
ic_set_dormant_pickable curve 0 {}
ic_geo_delete_family TEMP_TSF_FAM
ic_gui_set va_set(name)
ic_delete_geometry curve names crv.04 0
ic_curve point GEOM crv.04 {pnt.02 pnt.03}
ic_geo_delete_family WALL
ic_gui_set va_set(name)
ic_delete_geometry curve names crv.05 0
ic_curve point GEOM crv.05 {pnt.08 pnt.09}
ic_geo_new_family WALL
ic_boco_set_part_color WALL
ic_geo_cre_srf_crv_drv_srf WALL srf.03 crv.00 crv.04 1
ic_reinit_geom_objects
ic_set_dormant_pickable point 0 {}
ic_set_dormant_pickable curve 0 {}
ic_geo_cre_srf_crv_drv_srf WALL srf.04 crv.02 crv.05 1
ic_reinit_geom_objects
ic_set_dormant_pickable point 0 {}
ic_set_dormant_pickable curve 0 {}
ic_geo_new_family GEOM2
ic_boco_set_part_color GEOM2
ic_point {} GEOM2 pnt.12 0.027,0.027,0.227
ic_point {} GEOM2 pnt.13 0.027,0,0.227
ic_point {} GEOM2 pnt.14 0.027,0,0.173
ic_point {} GEOM2 pnt.15 0.027,0.027,0.173
ic_point {} GEOM2 pnt.16 -0.027,0.027,0.2
ic_point {} GEOM2 pnt.17 -0.027,0,0.2
ic_point {} GEOM2 pnt.18 -0.027,0,0.227
ic_point {} GEOM2 pnt.19 -0.027,0.027,0.227
ic_point {} GEOM2 pnt.20 -0.027,0.027,0.173
ic_point {} GEOM2 pnt.21 -0.027,0,0.173
ic_point {} GEOM2 pnt.22 -0.027,-0.027,0.173
ic_point {} GEOM2 pnt.25 0.027,-0.027,0.173
ic_point {} GEOM2 pnt.26 0.027,-0.027,0.227
ic_point {} GEOM2 pnt.27 -0.027,-0.027,0.227
ic_point {} GEOM2 pnt.28 -0.027,-0.027,0.2
ic_geo_new_family SOLID
ic_boco_set_part_color SOLID
ic_hex_initialize_blocking {point pnt.00 point pnt.01 point pnt.02 point pnt.03 point pnt.04 point pnt.05 point pnt.06 point pnt.07 point pnt.08 point pnt.09 point pnt.10 point pnt.11 point WALL.11 point WALL.13 point GEOM.13 point WALL.17 point WALL.18 point WALL.19 point WALL.21 point WALL.22 point pnt.12 point pnt.13 point pnt.14 point pnt.15 point pnt.16 point pnt.17 point pnt.18 point pnt.19 point pnt.20 point pnt.21 point pnt.22 point pnt.25 point pnt.26 point pnt.27 point pnt.28 curve crv.01 curve crv.03 curve crv.04 curve crv.05 curve srf.03e22 curve srf.03e21.2 curve srf.03e21.3 curve srf.03e23.2 curve srf.03e23.3 curve srf.04e32 curve srf.04e31.2 curve srf.04e31.3 curve srf.04e33.2 curve srf.04e33.3 surface srf.00 surface srf.01 surface srf.02 surface srf.03 surface srf.04} SOLID 0 101
ic_hex_switch_blocking root
ic_hex_unblank_blocks
ic_hex_multi_grid_level
ic_hex_switch_blocking root
ic_hex_split_grid 21 22 pnt.27 m GEOM OUT IN1 IN2 WALL GEOM2 SOLID
ic_hex_split_grid 21 69 pnt.15 m GEOM OUT IN1 IN2 WALL GEOM2 SOLID
ic_hex_split_grid 21 37 pnt.03 m GEOM OUT IN1 IN2 WALL GEOM2 SOLID
ic_hex_delete_blocks numbers 29 31
ic_hex_delete_blocks numbers 28
ic_hex_collapse_edge 73 89 join keep_first -version 101 fix_first
ic_hex_collapse_edge 69 85 join keep_first -version 101 fix_first
ic_hex_set_node_location z 0.2 -csys global node_numbers {{  73  } {  69  }}
ic_hex_unstruct_face_type
ic_hex_unstruct_face_type
ic_hex_create_yblock SOLID 110 106 73 109 105 69 GEOM OUT IN1 IN2 WALL GEOM2 SOLID
ic_hex_set_edge_projection 102 178 0 1 srf.03e23.2
ic_hex_set_edge_projection 21 25 0 1 srf.03e23.2
ic_hex_set_edge_projection 101 176 0 1 srf.03e23.2
ic_hex_set_edge_projection 101 102 0 1 srf.03e23.2
ic_hex_create_composite {srf.04e31.3 srf.04e31.2}
ic_hex_set_edge_projection 90 166 0 1 srf.04e31.3
ic_hex_set_edge_projection 86 90 0 1 srf.04e31.3
ic_hex_set_edge_projection 86 162 0 1 srf.04e31.3
ic_hex_set_edge_projection 70 74 0 1 srf.04e31.3
ic_hex_create_composite {srf.03e21.2 srf.03e21.3}
ic_hex_set_edge_projection 26 174 0 1 srf.03e21.2
ic_hex_set_edge_projection 22 26 0 1 srf.03e21.2
ic_hex_set_edge_projection 22 172 0 1 srf.03e21.2
ic_hex_set_edge_projection 113 114 0 1 srf.03e21.2
ic_boco_parts_dim GEOM
ic_boco_parts_dim GEOM2
ic_boco_parts_dim IN1
ic_boco_parts_dim IN2
ic_boco_parts_dim OUT
ic_boco_parts_dim SOLID
ic_boco_parts_dim VORFN
ic_boco_parts_dim WALL
ic_hex_project_face node_numbers { 22 69 172 168 } { 109 110 113 114 } { 22 26 69 73 } { 26 73 174 170 } { 86 105 90 106 } { 74 166 110 164 } { 70 162 109 160 } { 70 109 74 110 } { 101 102 105 106 } { 21 69 176 180 } { 25 73 178 182 } { 21 25 69 73 } { 73 170 182 184 } { 106 164 182 184 } { 110 170 164 184 } { 69 168 180 185 } { 109 168 160 185 } { 105 160 180 185 } WALL
ic_hex_set_mesh 102 106 n 15 h1rel 0.0 h2rel 0.0 r1 2 r2 2 lmax 0 uniform copy_to_parallel unlocked
ic_hex_set_mesh 109 113 n 30 h1rel 0.0 h2rel 0.0 r1 2 r2 2 lmax 0 uniform copy_to_parallel unlocked
ic_hex_set_mesh 110 74 n 15 h1rel 0.0 h2rel 0.0 r1 2 r2 2 lmax 0 uniform copy_to_parallel unlocked
ic_hex_set_mesh 102 178 n 10 h1rel 0.0 h2rel 0.0 r1 2 r2 2 lmax 0 uniform copy_to_parallel unlocked
ic_hex_set_mesh 101 102 n 10 h1rel 0.0 h2rel 0.0 r1 2 r2 2 lmax 0 uniform copy_to_parallel unlocked
ic_hex_set_mesh 90 166 n 10 h1rel 185185185185.0 h2rel 185185185185.0 r1 2 r2 2 lmax 1e+10 uniform copy_to_parallel unlocked
ic_hex_create_composite {srf.03e23.3 srf.03e23.2}
ic_hex_set_edge_projection 102 178 0 1 srf.03e23.3
ic_hex_set_edge_projection 21 25 0 1 srf.03e23.3
ic_hex_set_edge_projection 101 176 0 1 srf.03e23.3
ic_hex_set_edge_projection 101 102 0 1 srf.03e23.3
ic_hex_set_edge_projection 90 166 0 1 srf.04e31.3
ic_hex_set_edge_projection 86 90 0 1 srf.04e31.3
ic_hex_set_edge_projection 70 74 0 1 srf.04e31.3
ic_hex_set_edge_projection 86 162 0 1 srf.04e31.3
ic_hex_set_edge_projection 26 174 0 1 srf.03e21.2
ic_hex_set_edge_projection 22 26 0 1 srf.03e21.2
ic_hex_set_edge_projection 22 172 0 1 srf.03e21.2
ic_hex_set_edge_projection 113 114 0 1 srf.03e21.2
ic_boco_parts_dim GEOM
ic_boco_parts_dim GEOM2
ic_boco_parts_dim IN1
ic_boco_parts_dim IN2
ic_boco_parts_dim OUT
ic_boco_parts_dim SOLID
ic_boco_parts_dim VORFN
ic_boco_parts_dim WALL
ic_hex_project_face node_numbers { 26 73 174 170 } { 22 69 172 168 } { 109 110 113 114 } { 22 26 69 73 } { 25 73 178 182 } { 21 25 69 73 } { 101 102 105 106 } { 21 69 176 180 } { 70 162 109 160 } { 86 105 90 106 } { 74 166 110 164 } { 70 109 74 110 } WALL
ic_hex_set_mesh 90 166 n 10 h1rel 185185185185.0 h2rel 185185185185.0 r1 2 r2 2 lmax 1e+10 uniform copy_to_parallel unlocked
ic_hex_renew
ic_hex_set_mesh 182 73 n 5 h1rel 0.0 h2rel 0.0 r1 2 r2 2 lmax 0 uniform copy_to_parallel unlocked
ic_hex_set_mesh 73 170 n 5 h1rel 0.0 h2rel 0.0 r1 2 r2 2 lmax 0 uniform copy_to_parallel unlocked
ic_hex_set_mesh 106 182 n 5 h1rel 0.0 h2rel 0.0 r1 2 r2 2 lmax 0 uniform copy_to_parallel unlocked

BrolY August 29, 2011 10:31
It doesn't help, because I would like to understand why you did a quarter of O-grid at the junction. So the geometry file would help a lot more than the replay file ;)

Anyway, are you sure you need this quarter of O-grid ?

Robert@cfd August 29, 2011 11:02
No I am not sure, therefore I asked if you have some ideas about meshing a T-junction. I am not very familiar with meshing at all.

First I tested a single cylinder with an O-grid. My plan was to create an O-grid in the T-junction later, too.

I made the geometry in ICEM, so if you use my replay-file it creates the geometry and the blocking.

BrolY August 29, 2011 11:45
Is it the exact geometry you want to mesh ?
Because your 2nd tube is not cut at the junction with the main tube.

Anyway, I will have a look at it and let you know !

Robert@cfd September 6, 2011 11:00
Hi

Quote:
Originally Posted by BrolY (Post 322117)
Because your 2nd tube is not cut at the junction with the main tube.
What do you mean there? How can I fix my geometry?

Thx for your help!

akone November 1, 2011 21:10
T junction
 
Hi Everyone,

Please I'm very new to ICEM. I have a problem of creating a T juction in ICEM and applying an Ogrid mesh. Please how do I go about this?

Thanks in advance


akone

Sushilkumar November 2, 2011 02:35
1 Attachment(s)
You can use similar blocking.

akone November 2, 2011 03:10
Hi Sushilkumar,

Thanks for your reply. To be honest I'm not sure how to go about it. If you can give a step by step procedure, I'll be truly grateful.

Thanks
akone

Sushilkumar November 3, 2011 00:00
If you see in this 'T' there are three identical parts. You start with any one. I started with the middle cylinder.
Generate a block for middle cylinder.
Associate the edges on both the sides.
Split the block vertically.
Choosing end faces of these two adjacent blocks create 'O' grid.
Now, there will be total eight blocks.
Using extrude faces option, extrude the 4 blocks to left and 4 blocks to the right.
Move the vertices to respective locations.
Assign the respective edges to the curves.
This will generate the blocking for half cylinder (cylinder cut along axis).
Again using extrude generate the blocks for remaining half cylinder.
While doing this you will have to use 'merge vertices' option to sew the generated blocks together to form a complete 'O' grid.

I hope this is useful.

Robert@cfd November 3, 2011 13:25
1 Attachment(s)
Hi Sushilkumar

Good timing, I wasnt working on this icem problem the last time.
So I tried your guide, but I cant finish it. First I made the left cylinder. Then, for the part at the top I made a new block (initialize block) and split it. I made o-grid again and merged the vertices. But at the part in the right, I cant do this. So I tried "create block/extrude faces" like you said, but I cant do the angular faces in the correct manner...

Sushilkumar November 3, 2011 22:56
Please check,
http://www.4shared.com/folder/KBxQLFI3/_online.html

Robert@cfd November 4, 2011 11:08
2 Attachment(s)
Thx for the Howto. But this is a complete different way to block the T-junct. It works for the example where a small cylinder intersects a big one. But in my case, both have the same diameter and therefore the cells are getting really bad angles:

Sushilkumar November 4, 2011 11:39
Sorry, I didn't realized this.
In your post I guess you have done it in right way. To solve your problem try extruding the inclined faces. and then move the vertices to required place.

Hope this helps.

Robert@cfd November 4, 2011 12:16
1 Attachment(s)
Hi Sushilkumar

I just got the other blocking strategy by copying and 90°-rotating the first short cylinder and merging the vertices (see picture). But again my mesh is badly. Would be really nice, if you could show yours.

Thx!

Greetings,
Robert

Sushilkumar November 4, 2011 12:28
This blocking seems perfect. can you make the edges visible and post a snap? That will make the problem clear to me.

Robert@cfd November 4, 2011 12:35
1 Attachment(s)
Here you go:

Sushilkumar November 4, 2011 12:55
It seems okay. Just associate the edges carefully to the curves. You should get the right mesh.

Robert@cfd November 7, 2011 09:21
Hi

Is it possible, that you can show your mesh, plz?

Greetings,
Robert

Robert@cfd November 11, 2011 04:59
3 Attachment(s)
Thx for ur help Sushilkumar

I dis-associated your mesh and made some changes. Then I got nearly the same mesh, than I sent to you. I think with this blocking strategy, there have to be a bad crossover of the cells.
(what were the changes you made, I just can see the the moving of the corner points of the blocks, but this changes nothing in my opinion)

Here some pictures of my mesh:


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