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

ANSYS CFX Tutorial 7

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   January 6, 2009, 19:32
Default ANSYS CFX Tutorial 7
  #1
Sam
Guest
 
Posts: n/a
Hi,

I am working through the tutorials ad have come to tute 7 whihc is the free surface flow over a 2d bump. This tutorial is very applicable to what i would liek to do my thesis on.

When I try to solve the problem I get an error message which reads, "The density-difference buoyancy model is being used, but the buoyancy reference density has not been specified"

I have tried loading the session file supplied but it also comes up with the error when I try to solve it

Has anyone had a similar problem or any advice on how to resolve the problem?

Regards,

Sam
  Reply With Quote

Old   January 7, 2009, 07:29
Default Re: ANSYS CFX Tutorial 7
  #2
Rogerio Fernandes Brito
Guest
 
Posts: n/a
I did some meshes of this case. IF YOU WANT TO use these grids...

http://www.4shared.com/file/65772301..._Mr_Brito.html

http://www.4shared.com/file/65770211..._Mr_Brito.html

  Reply With Quote

Old   January 7, 2009, 17:03
Default Re: ANSYS CFX Tutorial 7
  #3
Sam
Guest
 
Posts: n/a
Thayou I will have a play,

I am very much learning CFD and know quite little about the topic at this stage, I have read a few books Do you know of any other ways to better understand using CFD to generate free surface flows?

I feel the problem may be in the setting up of my problem rather than the meshing but I will try again.

Thanks again,

Sam
  Reply With Quote

Old   January 7, 2009, 18:34
Default Re: ANSYS CFX Tutorial 7
  #4
Glenn Horrocks
Guest
 
Posts: n/a
Hi,

I agree the problem likely to be the setup, not the mesh. The error message refers to the buoyancy reference density - have you set it as it requests?

What version of CFX are you using?

Glenn Horrocks
  Reply With Quote

Old   January 7, 2009, 19:03
Default Re: ANSYS CFX Tutorial 7
  #5
Sam
Guest
 
Posts: n/a
I am currently using v11

I am about to have been reading CFX help

"For a flow containing a continuous phase and a dilute dispersed phase, you should set the buoyancy reference density to that of the continuous phase"

My understanding is that the reference density should be that of the water. Do you believe this is correct?

Regards,

Sam
  Reply With Quote

Old   January 8, 2009, 17:23
Default Re: ANSYS CFX Tutorial 7
  #6
Glenn Horrocks
Guest
 
Posts: n/a
Hi,

Yes, you are correct.

Glenn Horrocks
  Reply With Quote

Old   January 15, 2009, 08:10
Default Re: ANSYS CFX Tutorial 7
  #7
Peter
Guest
 
Posts: n/a
Did you select both "Air at 25C" and "Water" in the fluid list when defining the domain?
  Reply With Quote

Old   January 24, 2009, 20:48
Default Re: ANSYS CFX Tutorial 7
  #8
Leandro Resende
Guest
 
Posts: n/a
Hi Sam,

Besides what Peter said, you should also set density reference (under gravity force vectors) as the one of the lighter fluid.

In The density difference model only the heavier fluid suffers the gravity force.

See at Help how this model works.

hope was helpful
  Reply With Quote

Reply

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
Setting Pressure Boundary Conditions in ANSYS CFX Pre saisanthoshm88 CFX 21 February 22, 2017 17:50
Calculation of the Governing Equations Mihail CFX 7 September 7, 2014 07:27
URANS in ANSYS CFX brissyben CFX 3 October 6, 2009 18:35
I cannot open Ansys CFX in Workbench Pham Son Minh CFX 2 January 13, 2008 04:33
CFX bought by Ansys - good or bad?! Pete CFX 38 February 21, 2003 08:34


All times are GMT -4. The time now is 07:04.