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

BuoyantFoam and total pressure bc problem is a bug

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   January 23, 2008, 05:22
Default Can anybody just comment this
  #1
Member
 
Rosario Russo
Join Date: Mar 2009
Location: Trieste, Italy
Posts: 56
Rep Power: 17
ariorus is on a distinguished road
Can anybody just comment this please?

http://www.cfd-online.com/cgi-bin/Op...9416#POST19416

Thanks.

Rosario.
ariorus is offline   Reply With Quote

Old   January 27, 2008, 15:22
Default Hello, I'm writing here a s
  #2
Member
 
Rosario Russo
Join Date: Mar 2009
Location: Trieste, Italy
Posts: 56
Rep Power: 17
ariorus is on a distinguished road
Hello,

I'm writing here a short summary and an update of the issue.

I discovered that using totalPressure bc in buoyantFoam solver is not possible. The problem is that when pd is constructed via

volScalarField pd
(
IOobject
(
"pd",
runTime.timeName(),
mesh
),
p - rho*gh - pRef,
p.boundaryField().types()
);


the boundaryField types are not completely copied from p: i.e. the name for U phi and gamma are set to "undefined" and so the bc is made unusable.

I have seen that this is due the a precise constructor of totalPressureFvPatchScalarField.C, so I think there must be a reason why Devolopers did so.

By the way I realized that using this bc in buoyantFoam, choosing the isentropic relation to relate p and p0, would be misleading since the bc is used for the pd field which actually is a relative pressure: the isentropic relation would be wrong in this case.

I'm not sure whether I'm right or whether I misunderstood something: any comments to sustain or deny what I said would be much appreciated.

Thanks.

Rosario.
ariorus is offline   Reply With Quote

Old   January 27, 2008, 15:58
Default The easiest way around such in
  #3
Senior Member
 
Join Date: Mar 2009
Posts: 854
Rep Power: 22
henry is on a distinguished road
The easiest way around such initialization problems is to change the constructor to pd to a "read" constructor which would then allow you to specify all the information necessary for totalPressure and other complex BCs and then set the initial field values to p - rho*gh - pRef using an assignment statement. Also to apply a totalPressure BC to pd you will need to take into account the fact that it is pd rather than p in the formulation of the BC.

Henry
henry is offline   Reply With Quote

Old   January 28, 2008, 05:20
Default Ok. It is more or less what I
  #4
Member
 
Rosario Russo
Join Date: Mar 2009
Location: Trieste, Italy
Posts: 56
Rep Power: 17
ariorus is on a distinguished road
Ok. It is more or less what I did.

Thank you very much.

Rosario.
ariorus is offline   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
Total pressure problem tangd OpenFOAM Running, Solving & CFD 7 June 2, 2009 18:01
BuoyantFoam problem miquelvinya OpenFOAM Running, Solving & CFD 25 November 14, 2008 06:52
total pressure problem Ermanno CFX 5 February 19, 2007 18:16
total pressure in CFX Atit Koonsrisuk CFX 0 January 1, 2005 06:46
Total pressure to static pressure ratio roadracer Siemens 1 April 17, 2003 06:31


All times are GMT -4. The time now is 20:40.