[ICEM] prism generation

jsm · September 19, 2009, 00:48

Hi,

In ICEM CFD, how to avoid the pyramid elements generation while making prism layers. There is any best practices are available?

Kindly give your suggestions.

rikio · September 19, 2009, 23:48

Generate one layer of prism first, and then split this layer into as many layers as u want.

jsm · September 22, 2009, 05:04

Hi,

Thanks for your suggestion.

PSYMN · October 12, 2009, 14:00

I did intend to get to this, but I am traveling now and my internet connection is not good enough to post the ppt...

I will try later this week.

Simon

jsm · October 12, 2009, 23:45

Hi Simon,

Thanks for your efforts. Please post your presentation at your convenient time.

apantune · October 13, 2009, 17:58

JSM,
this might help you....

Mesh -> Global Mesh Setup -> Prism Meshing Parameter -> Advanced Prism Meshing Parameters -> Turn Off : Stop Columns, Refine Prism Boundary Turn On : Auto Reduction.

This setup will stop your prism layer before it intends to generate a pyramid element. You might not get the desired prism height.

Alex

apantune · October 13, 2009, 18:15

Quote:

Originally Posted by rikio

Generate one layer of prism first, and then split this layer into as many layers as u want.

Rikio,
if you have a very complex geometry and try to raise one single prism layer (with the total height to afterwards split it) the tetrahedrals sometimes can not be adequately acomodated. With this approach you smash the tetrahedrals by a certain amount in just one single steps (on the step by step approach the tetra are smoothed during the proccess). For complex geometries this can bring you some problems.

Regards,
Alex

jsm · October 14, 2009, 01:25

Hi Alex,

Thanks for your suggestion

. I am looking for similar kind of tips and tricks for prism mesh generation.

FYI : Simon will also post one presentation for prism mesh generation.

PSYMN · October 14, 2009, 15:01

Sorry for the long delay…

The ppt is here ftp://ftp.ansys.com/outgoing/simon/Prism_NoPyramids.pdf

The ppt was originally made for a customer using a combination of Fluent and CFD++, neither of which like pyramids very much, on models that were typically hundreds of millions of elements (they didn't want to just "try things").

Other solvers, such as CFX, would prefer pyramids to poor quality prisms, so this may not be the best settings for everyone... Which is why they are not the hard wired defaults... ICEM CFD is all about flexibility.

There are also some general prism tips in there.

Far · April 4, 2012, 16:42

Hi PSYMN

I want to write mesh for CFD++. Would you please guide me to set the boundary conditions for CFD++ and then output the mesh.

dnsantosh · April 18, 2012, 08:03

hi
am trying to generate tri/prism on my geometry which ha V shape , wen i try to generate prism by icem cfd it generates penetrating elements and pyramids, can anybody tell me how to avoid penetrating elements between V ( V angle 73 deg sides 80mm, 65mm and need 30mm prism height)

rikio · April 18, 2012, 10:16

Set the smoothing step to 0 under Global Prism Setting tab. Manually smooth after the prism generation.

PSYMN · April 18, 2012, 21:37

Another option (depending on your version) would be to go into Prism advanced settings and click the option for PrismV10... I think that was sorted out in later versions, but I forget when exactly.

shinde.gopal · February 8, 2013, 05:16

Quote:

Originally Posted by PSYMN

Sorry for the long delay…

The ppt is here ftp://ftp.ansys.com/outgoing/simon/Prism_NoPyramids.pdf

The ppt was originally made for a customer using a combination of Fluent and CFD++, neither of which like pyramids very much, on models that were typically hundreds of millions of elements (they didn't want to just "try things").

Other solvers, such as CFX, would prefer pyramids to poor quality prisms, so this may not be the best settings for everyone... Which is why they are not the hard wired defaults... ICEM CFD is all about flexibility.

There are also some general prism tips in there.

Thanks for preparing the stuff. But, I am not able to access the ftp. Can you please let me know if the file is still available at the same path and ftp is up. Thanks for the help.

Far · February 8, 2013, 05:34

http://www.cfd-online.com/Forums/ans...efinement.html

Enjoy !!!

PSYMN · February 8, 2013, 10:02

@ Shinde Gopal,

That pdf was from 2009... But I guess it is still relevant.

That whole FTP site was taken down. We have switched to Google.

Here is the google link.

https://docs.google.com/file/d/0ByIL...it?usp=sharing

shinde.gopal · February 11, 2013, 06:50

Thanks a lot

Quote:

Originally Posted by PSYMN

@ Shinde Gopal,

That pdf was from 2009... But I guess it is still relevant.

That whole FTP site was taken down. We have switched to Google.

Here is the google link.

https://docs.google.com/file/d/0ByIL...it?usp=sharing

shinde.gopal · February 11, 2013, 06:51

Quote:

Originally Posted by PSYMN

@ Shinde Gopal,

That pdf was from 2009... But I guess it is still relevant.

That whole FTP site was taken down. We have switched to Google.

Here is the google link.

https://docs.google.com/file/d/0ByIL...it?usp=sharing

Thanks alot

shinde.gopal · February 11, 2013, 07:08

@ Admin : Please delete this post

haristrawberry · September 22, 2017, 02:44

Hi,

Can anyone post the PPT or send it to haristrawberry@gmail.com

Thanks
Hari

September 19, 2009, 00:48	prism generation	#1
jsm Senior Member JSM Join Date: Mar 2009 Location: India Posts: 192 Rep Power: 20	Hi, In ICEM CFD, how to avoid the pyramid elements generation while making prism layers. There is any best practices are available? Kindly give your suggestions. __________________ With regards, JSM

September 19, 2009, 23:48		#2
rikio Senior Member Rikio Join Date: Mar 2009 Location: SH, China Posts: 182 Blog Entries: 1 Rep Power: 17	Generate one layer of prism first, and then split this layer into as many layers as u want. gnut1989 likes this.

September 22, 2009, 05:04		#3
jsm Senior Member JSM Join Date: Mar 2009 Location: India Posts: 192 Rep Power: 20	Hi, Thanks for your suggestion. __________________ With regards, JSM

October 12, 2009, 14:00	I'll get back to this.	#4
PSYMN Senior Member Simon Pereira Join Date: Mar 2009 Location: Ann Arbor, MI Posts: 2,663 Blog Entries: 1 Rep Power: 47	I did intend to get to this, but I am traveling now and my internet connection is not good enough to post the ppt... I will try later this week. Simon

October 12, 2009, 23:45		#5
jsm Senior Member JSM Join Date: Mar 2009 Location: India Posts: 192 Rep Power: 20	Hi Simon, Thanks for your efforts. Please post your presentation at your convenient time. __________________ With regards, JSM

October 13, 2009, 17:58	No Pyramid	#6
apantune New Member Alex Join Date: Oct 2009 Posts: 6 Rep Power: 16	JSM, this might help you.... Mesh -> Global Mesh Setup -> Prism Meshing Parameter -> Advanced Prism Meshing Parameters -> Turn Off : Stop Columns, Refine Prism Boundary Turn On : Auto Reduction. This setup will stop your prism layer before it intends to generate a pyramid element. You might not get the desired prism height. Alex

October 14, 2009, 01:25		#8
jsm Senior Member JSM Join Date: Mar 2009 Location: India Posts: 192 Rep Power: 20	Hi Alex, Thanks for your suggestion. I am looking for similar kind of tips and tricks for prism mesh generation. FYI : Simon will also post one presentation for prism mesh generation. __________________ With regards, JSM

October 14, 2009, 15:01	PDF of Prism tips.	#9
PSYMN Senior Member Simon Pereira Join Date: Mar 2009 Location: Ann Arbor, MI Posts: 2,663 Blog Entries: 1 Rep Power: 47	Sorry for the long delay… The ppt is here ftp://ftp.ansys.com/outgoing/simon/Prism_NoPyramids.pdf The ppt was originally made for a customer using a combination of Fluent and CFD++, neither of which like pyramids very much, on models that were typically hundreds of millions of elements (they didn't want to just "try things"). Other solvers, such as CFX, would prefer pyramids to poor quality prisms, so this may not be the best settings for everyone... Which is why they are not the hard wired defaults... ICEM CFD is all about flexibility. There are also some general prism tips in there. pz21, Mazze[ITA], Ram and 2 others like this.

April 4, 2012, 16:42	Cfd++	#10
Far Super Moderator Sijal Join Date: Mar 2009 Location: Islamabad Posts: 4,553 Blog Entries: 6 Rep Power: 54	Hi PSYMN I want to write mesh for CFD++. Would you please guide me to set the boundary conditions for CFD++ and then output the mesh. Last edited by Far; April 5, 2012 at 05:48.

April 18, 2012, 08:03	problem in prism layer	#11
dnsantosh New Member SANTOSH Join Date: Jan 2012 Posts: 10 Rep Power: 14	hi am trying to generate tri/prism on my geometry which ha V shape , wen i try to generate prism by icem cfd it generates penetrating elements and pyramids, can anybody tell me how to avoid penetrating elements between V ( V angle 73 deg sides 80mm, 65mm and need 30mm prism height)

April 18, 2012, 10:16		#12
rikio Senior Member Rikio Join Date: Mar 2009 Location: SH, China Posts: 182 Blog Entries: 1 Rep Power: 17	Set the smoothing step to 0 under Global Prism Setting tab. Manually smooth after the prism generation.

April 18, 2012, 21:37		#13
PSYMN Senior Member Simon Pereira Join Date: Mar 2009 Location: Ann Arbor, MI Posts: 2,663 Blog Entries: 1 Rep Power: 47	Another option (depending on your version) would be to go into Prism advanced settings and click the option for PrismV10... I think that was sorted out in later versions, but I forget when exactly. __________________ ----------------------------------------- Please help guide development at ANSYS by filling in these surveys Public ANSYS ICEM CFD Users Survey This second one is more general (Gambit, TGrid and ANSYS Meshing users welcome)... CFD Online Users Survey

February 8, 2013, 05:34		#15
Far Super Moderator Sijal Join Date: Mar 2009 Location: Islamabad Posts: 4,553 Blog Entries: 6 Rep Power: 54	http://www.cfd-online.com/Forums/ans...efinement.html Enjoy !!!

February 8, 2013, 10:02		#16
PSYMN Senior Member Simon Pereira Join Date: Mar 2009 Location: Ann Arbor, MI Posts: 2,663 Blog Entries: 1 Rep Power: 47	@ Shinde Gopal, That pdf was from 2009... But I guess it is still relevant. That whole FTP site was taken down. We have switched to Google. Here is the google link. https://docs.google.com/file/d/0ByIL...it?usp=sharing Kontestator and majid fahim like this. __________________ ----------------------------------------- Please help guide development at ANSYS by filling in these surveys Public ANSYS ICEM CFD Users Survey This second one is more general (Gambit, TGrid and ANSYS Meshing users welcome)... CFD Online Users Survey

February 11, 2013, 07:08		#19
shinde.gopal New Member Gopal Shinde Join Date: Sep 2009 Location: Pune, India Posts: 28 Rep Power: 16	@ Admin : Please delete this post Last edited by shinde.gopal; February 11, 2013 at 07:29.

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