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

how to change boundary type in unsteay calculation

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

Reply
 
LinkBack Thread Tools Display Modes
Old   January 7, 2002, 03:01
Default how to change boundary type in unsteay calculation
  #1
cfdfans
Guest
 
Posts: n/a
How to change boundary type in unsteay calculation? when T=t0 ,I set boundary condition as WALL and begin calculate. when T=t1, I want to change the boundary condition as interior . How to get it with UDF of fluent.

thanks
  Reply With Quote

Old   January 7, 2002, 07:18
Default Re: how to change boundary type in unsteay calcula
  #2
Jin-Wook LEE
Guest
 
Posts: n/a
I think that 'WALL' can't(and shoudn't) be changed to 'INTERIOR' in CFD(including Fluent) calculation.

CFD is basically BVP(Boundary Value Problem). 'WALL' means boundary. So, how can BOUNDARY be changed to INTERIOR ?

Sincerely, Jinwook

  Reply With Quote

Old   January 7, 2002, 11:06
Default Re: how to change boundary type in unsteay calcula
  #3
Ashutosh
Guest
 
Posts: n/a
I think interior in Fluent means same material both sides, otherwise it has to be a wall.
  Reply With Quote

Old   January 7, 2002, 22:34
Default Re: how to change boundary type in unsteay calcula
  #4
cfdfans
Guest
 
Posts: n/a
In my problem ,chamber have a valve .when T=t0 the valve is close, T=t1 the valve is open. how can i simulate this process.
  Reply With Quote

Old   January 8, 2002, 05:05
Default Re: how to change boundary type in unsteay calcula
  #5
Jin-Wook LEE
Guest
 
Posts: n/a
I think that your problem is IVP(Initial Value Problem). From the T=t0 to T=t1, there is no flow because the valve is closed. Then, I guess that your interest should be focused on the flow field from T=t1.

Then, generated the mesh without valve if valve is entirely removed from the chamber. Or generate the mesh including the valve for open position if the valve is still in the chamber, and let it as 'SOLID'.

And, finaly you can simulate the flow field from the T=t1 with initial condition of 'REST' everywhere.

Sincerely, Jinwook

  Reply With Quote

Old   January 9, 2002, 09:16
Default Re: how to change boundary type in unsteay calcula
  #6
Bipin
Guest
 
Posts: n/a
Hi,

The interior can be declared as wall. Fluent in this case create a wall shadow.

The better way for you would be define an interface between two surfaces. This will allow the flow of fluid across the zones.

If you dont want to allow the flow across this zones at time t1 (N time step)

go to solve--->Execute Command

Enter the time step corresponding to required time.

Enter the text command as /define/grid-interfaces/delete "interface-name"

This will delete the interface and would not allow the flow.

Hope this helps

Bipin
  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
Fluent msh and cyclic boundary cfdengineering OpenFOAM Other Meshers: ICEM, Star, Ansys, Pointwise, GridPro, Ansa, ... 48 January 25, 2013 04:28
Pressure instability with rhoSimpleFoam daniel_mills OpenFOAM Running, Solving & CFD 44 February 17, 2011 18:08
RPM in Wind Turbine Pankaj CFX 9 November 23, 2009 05:05
Problem with compile the setParabolicInlet ivanyao OpenFOAM Running, Solving & CFD 6 September 5, 2008 20:50
How to change boundary type at calculation time? Stanislav Kraev FLUENT 0 December 4, 2006 04:33


All times are GMT -4. The time now is 00:46.