CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > CONVERGE

CHT simulation

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   March 6, 2017, 04:49
Default CHT simulation
  #1
New Member
 
Join Date: Dec 2016
Posts: 13
Rep Power: 8
joescor2 is on a distinguished road
Hi!.I have a query: I ran a simulation of a combustion case without solid material, which one don't had any problem but when I ran a CHT simulation with material on chamber combustion this one went faster than the first one. Are ther any explanation for this? I think that there are something wrong.

During the CHT simulation frequently the running shows me

problem with the number of regions in rank 2
problem with the number of regions in rank 3
problem with the number of regions in rank 4
problem with the number of regions in rank 5
problem with the number of regions in rank 6
joescor2 is offline   Reply With Quote

Old   March 6, 2017, 12:09
Default
  #2
Member
 
Yaju's Avatar
 
Yajuvendra Shekhawat
Join Date: Mar 2017
Location: Convergent Science, Madison WI
Posts: 51
Rep Power: 7
Yaju is on a distinguished road
Hi joescor2,

If you are using the same grid settings with the same machines and appropriate load balancing to run these two problems (with and without CHT), the CHT simulation should take more time. So, please check whether the same grid settings are used (inputs.in-for base grid size, amr.in and embedded.in), same machines are used, and load balancing is good (number of cells on different machines in metis_map.out or cell_count_ranks.out).

The messages of "problem with the number of regions in rank #" are output when CONVERGE does load balancing. With a CHT simulation, there is load balancing occurring across multiple streams which causes these messages, but it should not affect your results.
__________________
Yajuvendra Shekhawat
Research Engineer - Applications Group
CONVERGECFD
Yaju is offline   Reply With Quote

Old   March 7, 2017, 04:39
Default
  #3
New Member
 
Join Date: Dec 2016
Posts: 13
Rep Power: 8
joescor2 is on a distinguished road
Thanks, I have checked all the parameters and everything is fine. I'm using the step variable algorithm, but I don't understand why the step time is longer in without the CHT.

When I checked the file time.out all the CFL values are different in both cases.

The only parameter that I changed was the wall temperature because in case without CHT it's fixed by me while in the other case it's calculated by converge.

In case whitout CHT de limiter is cfld but in the other case there's no limiter time.

Last edited by joescor2; March 7, 2017 at 06:35.
joescor2 is offline   Reply With Quote

Reply

Tags
cht, combustion, conjugate, simulation

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Adding heat source to chtMultiRegionFoam maddalena OpenFOAM Programming & Development 61 February 17, 2018 09:33
Some questions about flow boiling simulation in Fluent beastieboys6 FLUENT 8 November 21, 2017 00:47
Simulation FPEs - turbulence for transient and steady-state? DaveR OpenFOAM Running, Solving & CFD 5 March 5, 2017 16:06
Transient CHT Simulation slow variable increase marcel_jay CFX 8 May 2, 2016 18:11
Huge file sizes when Running VOF simulation aarratia FLUENT 0 May 8, 2014 13:27


All times are GMT -4. The time now is 10:05.