CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Running, Solving & CFD

Boundary condition

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   May 31, 2010, 11:52
Default Boundary condition
  #1
Senior Member
 
Daniele
Join Date: Feb 2010
Posts: 134
Rep Power: 16
Daniele111 is on a distinguished road
Hi All
If i want impose BC, in k-s model, for k, epsilon and U on inlet ma not pressure, How change 0/p file?
Thanks
Daniele111 is offline   Reply With Quote

Old   May 31, 2010, 13:54
Default
  #2
Senior Member
 
Daniele
Join Date: Feb 2010
Posts: 134
Rep Power: 16
Daniele111 is on a distinguished road
I simulate atmospheric boundary layer and on outlet I impose zero gradient for the pressure, but in the paper that I use like reference don't speak about pressure condition on other part of boundary.
Daniele111 is offline   Reply With Quote

Old   May 31, 2010, 14:10
Default
  #3
Senior Member
 
Daniele
Join Date: Feb 2010
Posts: 134
Rep Power: 16
Daniele111 is on a distinguished road
And when I run my case i have this error:

DILUPBiCG: Solving for Ux, Initial residual = 1, Final residual = 1.88883e-21, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 1, Final residual = 0.0159314, No Iterations 2
DICPCG: Solving for p, Initial residual = 1, Final residual = 0.00459912, No Iterations 15
time step continuity errors : sum local = 17748.9, global = 66.9892, cumulative = 66.9892
#0 Foam::error:rintStack(Foam::Ostream&) in "/home/acconcia/OpenFOAM/OpenFOAM-1.6/lib/linuxGccDPOpt/libOpenFOAM.so"
#1 Foam::sigFpe::sigFpeHandler(int) in "/home/acconcia/OpenFOAM/OpenFOAM-1.6/lib/linuxGccDPOpt/libOpenFOAM.so"
#2 Uninterpreted:
#3 Foam::divide(Foam::Field<double>&, Foam::UList<double> const&, Foam::UList<double> const&) in "/home/acconcia/OpenFOAM/OpenFOAM-1.6/lib/linuxGccDPOpt/libOpenFOAM.so"
#4 void Foam::divide<Foam::fvPatchField, Foam::volMesh>(Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh>&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&) in "/home/acconcia/OpenFOAM/OpenFOAM-1.6/lib/linuxGccDPOpt/libincompressibleRASModels.so"
#5 Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> > Foam:perator/<Foam::fvPatchField, Foam::volMesh>(Foam::tmp<Foam::GeometricField<doub le, Foam::fvPatchField, Foam::volMesh> > const&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&) in "/home/acconcia/OpenFOAM/OpenFOAM-1.6/lib/linuxGccDPOpt/libincompressibleRASModels.so"
#6 Foam::incompressible::RASModels::kEpsilon::correct () in "/home/acconcia/OpenFOAM/OpenFOAM-1.6/lib/linuxGccDPOpt/libincompressibleRASModels.so"
#7
in "/home/acconcia/OpenFOAM/OpenFOAM-1.6/applications/bin/linuxGccDPOpt/simpleFoam"
#8 __libc_start_main in "/lib/tls/i686/cmov/libc.so.6"
#9
at /usr/src/packages/BUILD/glibc-2.9/csu/../sysdeps/i386/elf/start.S:122
Floating point exception




Idea????
Daniele111 is offline   Reply With Quote

Old   June 1, 2010, 08:41
Default
  #4
Member
 
Francois Gallard
Join Date: Mar 2010
Location: Toulouse, France
Posts: 43
Rep Power: 16
fgal is on a distinguished road
Hi Daniele,
The solver does not accomplish the resolution of the linear systems properly. This can come from the boundary conditions, the mesh, the numerical schemes or their combination...
You could try first to use smoothSolver and GaussSeidel instead of DILU in your system/fvSolution file, which seems to be more efficient in my experience :

solver smoothSolver;
smoother GaussSeidel;
tolerance 1e-8;
relTol 0;
nSweeps 1;

Hope it helps...
fgal is offline   Reply With Quote

Old   June 9, 2010, 15:32
Default
  #5
Senior Member
 
Daniele
Join Date: Feb 2010
Posts: 134
Rep Power: 16
Daniele111 is on a distinguished road
Hi
Someone just simulated atmospheric boundary layer? What are correct boundary condition for p? An k epsilon? Is correct use wallShearStress to compute the stress at bottom?
Best regards
Daniele111 is offline   Reply With Quote

Old   June 10, 2010, 12:54
Default
  #6
Senior Member
 
Daniele
Join Date: Feb 2010
Posts: 134
Rep Power: 16
Daniele111 is on a distinguished road
What is there of wrong in my boundary condition for atmospheric boundary layer? Help me thanks!
Best regards
Attached Files
File Type: gz 0.tar.gz (2.0 KB, 3 views)
Daniele111 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
Boundary Conditions Thomas P. Abraham Main CFD Forum 20 July 7, 2013 06:05
How exactly the "pressure outlet" bdry condition compute properties on the boundary? yating9901 FLUENT 3 June 28, 2010 13:26
Transient outlet boundary condition problem jwillie2000 CFX 1 December 7, 2009 18:07
How to set boundary condition in Fluent for the fo Peiyong FLUENT 1 November 10, 2006 12:44
How to resolve boundary condition problem? sam FLUENT 2 July 20, 2003 03:19


All times are GMT -4. The time now is 22:37.