# Grid dependency study in building heat transfer

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

 April 10, 2013, 13:20 Grid dependency study in building heat transfer #1 Member   sunil Join Date: Jul 2012 Location: Bangalore Posts: 89 Rep Power: 5 Hello sir, I am doing my M Tech Project on building heat transfer.i have considered single room of dimensions 4*4*4 m.i am applying heat flux to the walls heat flux is varying with time.i have to run my simulation for 24 hours(Total time = 86400 s) my question is for grid dependency study either i have to very both time step size and grid size(space and time) or any one of them is enough because it takes too much of computational time even for time step of 10 s to solve for given total time Results which i am interested are 1.Average room temperature 2.avg wall temperature Thank you sir

April 10, 2013, 16:17
#2
Member

Dmitry
Join Date: Nov 2011
Posts: 45
Rep Power: 5
Quote:
 Originally Posted by sunilpatil Hello sir, I am doing my M Tech Project on building heat transfer.i have considered single room of dimensions 4*4*4 m.i am applying heat flux to the walls heat flux is varying with time.i have to run my simulation for 24 hours(Total time = 86400 s) my question is for grid dependency study either i have to very both time step size and grid size(space and time) or any one of them is enough because it takes too much of computational time even for time step of 10 s to solve for given total time Results which i am interested are 1.Average room temperature 2.avg wall temperature Thank you sir
see attached
user54862_pic391_1340124620.jpg

 April 10, 2013, 21:00 #3 Super Moderator   Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 10,669 Rep Power: 84 This is why I strongly recommend using adaptive timestepping. Set adaptive time stepping to home in on 3-5 coeff loops per iteration, then yoru timestep is automatically calculated and you have one less variable to do a sensitivity analysis on.

 April 11, 2013, 02:10 Grid dependency #4 Member   sunil Join Date: Jul 2012 Location: Bangalore Posts: 89 Rep Power: 5 Hello sir, Thank you for reply. i will try to run solver with adaptive time stepping as you suggested Thank you sir Sunil Patil

April 11, 2013, 09:26
#5
Senior Member

Mr CFD
Join Date: Jun 2012
Location: Britain
Posts: 289
Rep Power: 6
Quote:
 Originally Posted by imnull see attached Attachment 20646
Hi,

Where did you get the presentation from? What's the title of the presentation?

Thanks

 Thread Tools Display Modes Linear Mode

 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 OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post hinca CFX 15 January 26, 2014 18:11 pathakamit FLUENT 1 April 30, 2013 04:07 shields FLUENT 13 October 14, 2012 15:44 Chuck Leakeas Main CFD Forum 2 May 26, 2000 11:18 ranjeet Main CFD Forum 6 September 1, 1999 06:41

All times are GMT -4. The time now is 22:41.