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

Surface to surface vs. Participating media. Slow progress.

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   August 19, 2016, 07:41
Question Surface to surface vs. Participating media. Slow progress.
  #1
New Member
 
Ivan Pastukhov
Join Date: Nov 2015
Posts: 4
Rep Power: 11
Pastukhov is on a distinguished road
Hi all!

I'm currently modelling HVAC in some room but have some difficulties with calculation progress using "surface to surface" both of Discrete Transfer and Monte-Carlo radiation models.
For model having ~15,000,000 tetra/hexa elements i've got approximately 150 iterations per 12 hours for participating media case. Don't know why, but when i switch to "surface to surface"
implementation no one (!) iteration had been completed per 12 hours. Just in case there is huge glazing of one side of the room.

Following settings are being used:

- ~15,000,000 tera/hexa elements with 2 non-conformal mesh interfaces;
- steady state;
- Gas: air ideal gas;
- Heat transfer model: thermal energy;
- Turbulence: k-eps;
- radiation: discrete ordinates (s2s), number of rays (12), spectral model - gray;
- glazing BC - fixed radiation heat flux, fixed outer temperature and heat transfer coefficient;
- PC: 8 x Xeon 2.5GHz, 32Gb OM, 60 Gb free space
- Ansys 16.2.

I guess that s2s implementation must be simplier that PM, isn't it?

Does anybody know how comes it and how can i fix it?
Can it depends on number of surfaces or it's shape (curving, edge length, etc.)?

Excuse me for my poor English.
Thanks in advance!
Pastukhov is offline   Reply With Quote

Reply

Tags
discrete transfer, monte carlo, participating media, radiation, surface to surface


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
Modelling CO2 adsorption (porous media + surface reaction) asfrallego FLUENT 1 October 27, 2024 09:15
Normal - Helical Surface m. malik Main CFD Forum 3 February 3, 2006 13:56
free surface & porous media Markus Main CFD Forum 2 July 15, 2005 04:24
solid edge problem....can you help? cindy Main CFD Forum 3 April 5, 2004 14:43
CFX4.3 -build analysis form Chie Min CFX 5 July 13, 2001 00:19


All times are GMT -4. The time now is 18:22.