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

Need help initializing materials

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

Reply
 
LinkBack Thread Tools Display Modes
Old   May 15, 2010, 20:50
Default Need help initializing materials
  #1
New Member
 
Liam
Join Date: May 2010
Posts: 1
Rep Power: 0
Civil_Liam is on a distinguished road
For what I am sure is a mistake on my part, fluent believes there is air flow in my system instead of water (I want it to be water). I didn't realize this until I calculated the mass flow rate across my inlet and it gave me values that would only correspond with air, i.e., 0.98 kg/s for a 2x1 m inlet with a velocity of .4 m/s --> would mean density is 1.23 kg/m3 (that of air). Plots, surface integral averages and contours reveal this same density value throughout my CV.

Starting from scratch, this is my procedure:

1.) open case/data file (provided by professor)---> cavity0
2.) define materials --> choose water (leave density constant at 998 kg/m3) --> create
3.)define boundary conditions--> inlet---> change velocity to .4m/s--> ok
4.) solve-->initialize-->initialize--> compute from inlet and change x velocity to .4m/s--> initialize --> close
--> save (write case/data to new file)
5.) iterate till convergence.

Is there something fundamental that I am not picking up on or is a step left out?

I have tried this process a few different ways but still get the same result.
I see for Report --> Reference values that values are able to be altered, but I do not understand what this does and in what order it should be done. Even after toying with values in this reference value section, figures remain the same in all utilities.

I am new to this forum and to the fluent platform so please excuse any unobserved etiquette or lack of information that typically may be needed in order for someone to address this question. I will be happy to respond with further information if need be. Thanks for any help

visual of flow field is below

[IMG][/IMG]
Civil_Liam is offline   Reply With Quote

Old   May 16, 2010, 10:28
Default
  #2
Senior Member
 
Chris
Join Date: Jul 2009
Location: Ohio, USA
Posts: 169
Rep Power: 8
Chris D is on a distinguished road
Go to Define-->Boundary Condtions, select the fluid zone, and change the material from air to water.
Chris D is offline   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
mass flow in is not equal to mass flow out saii CFX 2 September 18, 2009 08:07
new materials in fluent by mixing other materials Anna FLUENT 0 January 18, 2009 05:53
Reaction help!! Harry CFX 4 October 30, 2008 11:11
query regarding role of initializing in a solving Kishore FLUENT 2 July 4, 2007 23:23
Two-Phase Buoyant Flow Issue Miguel Baritto CFX 4 August 31, 2006 12:02


All times are GMT -4. The time now is 07:24.