Does Gambit has a maximum allowable grid number?

spartan1516 · February 12, 2010, 16:19

I tried to generate a mesh by Gambit with proposed grid size about 20 million cells. Unfortunately I found when the grid size is more than 19 millions (roughly), the gambit can not save the dbs file, or it quits running when it tried to export the .msh file.

I received errors message like, "Assertion failed in meshpacket.cc", mesh_packeet ->minMeshPrt while meshing, can not allocate dynamic memory and so on.

I tested by using a PC running 64 Vista Operate System with a 32 bit Gambit software (Windows can only support 32 bit Gambit) and a 64 bit Linux Server with 64 bit version Gambit.

Does anyone know what the maximum mesh Gambit can handle? What is the biggest problem Fluent can handle either?

Thanks,
Kyle

bobmalaria · February 22, 2010, 08:19

Hi,

I guess that you reached the physical limit your RAM memory can handle. With a 32bit system only somewhat around 3GB can be allocated, with a 64bit system you can use way more. So chech the RAM available and consider upgrading or maybe another meshing technique

spartan1516 · February 22, 2010, 10:24

I am using 64 bit system with 24GB memory, so I don' think it is due to the RAM.

mitra · February 22, 2010, 10:51

yes, it has a limit for maximum number of grid (number of faces and volumes) you can change the defaults in edit/default/menue.

spartan1516 · February 22, 2010, 13:18

Maybe in some place, but I really can not find the option under Edit Default Tab.
Can you point out the sub-Tab and the variable name?
Thanks,

rieuk · March 16, 2010, 22:09

AFAIK there is no 64 bit release of GAMBIT. Could this be the problem?

praveenkumar · March 17, 2010, 00:33

Quote:

Originally Posted by spartan1516

I tried to generate a mesh by Gambit with proposed grid size about 20 million cells. Unfortunately I found when the grid size is more than 19 millions (roughly), the gambit can not save the dbs file, or it quits running when it tried to export the .msh file.

I received errors message like, "Assertion failed in meshpacket.cc", mesh_packeet ->minMeshPrt while meshing, can not allocate dynamic memory and so on.

I tested by using a PC running 64 Vista Operate System with a 32 bit Gambit software (Windows can only support 32 bit Gambit) and a 64 bit Linux Server with 64 bit version Gambit.

Does anyone know what the maximum mesh Gambit can handle? What is the biggest problem Fluent can handle either?

Thanks,
Kyle

hi am praveen

iam also doing complex geometry design, i.e mass transfer column design
wer design is related to more different shapes, i too found the same problem. upto my knowledge, split the whole the geometry into small pecies and try to mesh with simple interval size wer u dont require much accurate analysis.

and perfect mesh will save what ever be the compture confi.

Karatix · March 25, 2010, 10:08

Hi,

just want to say, I think that Gambit runs on 32bit and if you use XP you cannot use more 3GB even if you have more. I have similar problems with CFX 10.0. If the mesh is too accurate the meshing stops after some time.

Even if the mesh generator can handle the amount of cells, solvers sometimes can't.

Maybe sounds strange, but could you scale your problem down or split your analysis or do you have cross flow.

Good luck,

Karatix

February 12, 2010, 16:19	Does Gambit has a maximum allowable grid number?	#1
spartan1516 New Member Kyle Join Date: Feb 2010 Posts: 5 Rep Power: 16	I tried to generate a mesh by Gambit with proposed grid size about 20 million cells. Unfortunately I found when the grid size is more than 19 millions (roughly), the gambit can not save the dbs file, or it quits running when it tried to export the .msh file. I received errors message like, "Assertion failed in meshpacket.cc", mesh_packeet ->minMeshPrt while meshing, can not allocate dynamic memory and so on. I tested by using a PC running 64 Vista Operate System with a 32 bit Gambit software (Windows can only support 32 bit Gambit) and a 64 bit Linux Server with 64 bit version Gambit. Does anyone know what the maximum mesh Gambit can handle? What is the biggest problem Fluent can handle either? Thanks, Kyle

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February 22, 2010, 08:19		#2
bobmalaria Member Martin H. Join Date: May 2009 Posts: 31 Rep Power: 17	Hi, I guess that you reached the physical limit your RAM memory can handle. With a 32bit system only somewhat around 3GB can be allocated, with a 64bit system you can use way more. So chech the RAM available and consider upgrading or maybe another meshing technique

February 22, 2010, 10:24		#3
spartan1516 New Member Kyle Join Date: Feb 2010 Posts: 5 Rep Power: 16	I am using 64 bit system with 24GB memory, so I don' think it is due to the RAM.

February 22, 2010, 10:51		#4
mitra New Member Mitra Karami Join Date: Feb 2010 Posts: 4 Rep Power: 16	yes, it has a limit for maximum number of grid (number of faces and volumes) you can change the defaults in edit/default/menue.

February 22, 2010, 13:18		#5
spartan1516 New Member Kyle Join Date: Feb 2010 Posts: 5 Rep Power: 16	Maybe in some place, but I really can not find the option under Edit Default Tab. Can you point out the sub-Tab and the variable name? Thanks,

March 16, 2010, 22:09		#6
rieuk Senior Member Pavan Join Date: May 2009 Location: Melbourne Posts: 101 Rep Power: 17	AFAIK there is no 64 bit release of GAMBIT. Could this be the problem?

March 25, 2010, 10:08		#8
Karatix New Member Karatix Join Date: Sep 2009 Posts: 22 Rep Power: 17	Hi, just want to say, I think that Gambit runs on 32bit and if you use XP you cannot use more 3GB even if you have more. I have similar problems with CFX 10.0. If the mesh is too accurate the meshing stops after some time. Even if the mesh generator can handle the amount of cells, solvers sometimes can't. Maybe sounds strange, but could you scale your problem down or split your analysis or do you have cross flow. Good luck, Karatix