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

Modelling Ceiling Fan

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

Reply
 
LinkBack Thread Tools Display Modes
Old   March 21, 2000, 12:10
Default Modelling Ceiling Fan
  #1
suitto
Guest
 
Posts: n/a
Dear All, Using Fluent5.3, i am trying to model the flow inside a room (5x5x3m) with a ceiling fan (blade radius 0.6m). The gap between the fan and ceiling is assumed to be 0.5m. There is a window on one side of the wall (1.5x1.0m).

i have tried to model the fan as a 'fan b.c.'. The airflow velocity measured beneath the fan was measured to be 1.5m/s. So using Bernoulli's Eqn, and assume the air above the fan is 0m/s, the pressure jump across the fan is computed to be -1.378Pa.

i am using the k-e turb model & standard wall function. Convergence for u,v,w,k&e were excellent but the continuity eqn residue (non-normalised) hangs above 0.001.

Please advise on where could have gone wrong, and is my modelling correct. Thanks a lot.

ps: i have drawn a jpeg diagram of the setup. i dunno how to post it on this forum. So email me if you would like to take a closer look at the problem.
  Reply With Quote

Old   March 21, 2000, 12:46
Default Re: Modelling Ceiling Fan
  #2
Chetan Polavaram
Guest
 
Posts: n/a
Hi

I have had the same problem when I tried to model turbulent flow thro straight pipes.

One thing I did was adapted the grid based on TKE. You can try doing the same thing. After adapting if you find the residuals levelling off at the same point where they did earlier then just go with what you have. If the residuals level off lower than what they did then you can try adapting till there is no considerable change in pressure(grid independent). One more thing you could do is to reduce the under-relaxation factors.

Good luck, Chetan
  Reply With Quote

Reply

Thread Tools
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 On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Inlet shapes for modelling a fan in an inlet duct buzzybee CFX 10 June 11, 2009 20:15
simulation of ceiling fan Raj FLUENT 0 October 3, 2008 05:21
Negative Pressure in fan modelling Jenny CFX 3 September 30, 2007 08:47
Fan Modelling Problem in CFX Jenny CFX 8 September 11, 2007 13:59
Modelling a fan Richard CFX 3 October 10, 2006 09:48


All times are GMT -4. The time now is 03:09.