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

FOAM FATAL ERROR: Continuity error cannot be removed by adjusting the outflow.

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

Like Tree1Likes
  • 1 Post By HorstPeter

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   December 15, 2016, 07:15
Default FOAM FATAL ERROR: Continuity error cannot be removed by adjusting the outflow.
  #1
New Member
 
Join Date: May 2016
Posts: 25
Rep Power: 6
mgab is on a distinguished road
Hello,
I'm trying to run a simulation it gives the following error:
Code:
--> FOAM FATAL ERROR: 
Continuity error cannot be removed by adjusting the outflow.
Please check the velocity boundary conditions and/or run potentialFoam to initialise the outflow.
Total flux              : 105.971
Specified mass inflow   : 546831
Specified mass outflow  : 0
Adjustable mass outflow : 0
The geometry consists in a mixing elbow with constant diameter on the bent tube.

This are the initial conditions for velocity and pressure:
Velocity
Code:
dimensions      [0 1 -1 0 0 0 0];

internalField   uniform (0 0 0);

boundaryField
{
    wall
    {
        type            noSlip;
    }

    inletSmall
    {
//        type            zeroGradient;
        type            fixedValue;
        value            uniform (0 1.2 0);    
    }

    inletBig
    {
//        type            zeroGradient;
        type            fixedValue;
        value            uniform (0.4 0 0);
    }

    outlet
    {
        type            zeroGradient;
    }
}
Pressure
Code:
dimensions      [0 2 -2 0 0 0 0];

internalField   uniform 0;

boundaryField
{
    wall
    {
        type            zeroGradient;
    }

    inletSmall
    {
//        type            fixedValue;
//        value            uniform 1010.325;
        type            zeroGradient;
    }

    inletBig
    {
//        type            fixedValue;
//        value            uniform 1010.325;
        type            zeroGradient;
    }

    outlet
    {
//        type            fixedValue;
//        value            uniform 0;
        type            zeroGradient;
    }
}
If i use the commented options (zeroGradient velocity and set pressure) no errors are given.

Does anyone know how to help me?
mgab is offline   Reply With Quote

Old   December 15, 2016, 08:23
Default
  #2
New Member
 
Peter Lustig
Join Date: Dec 2016
Posts: 3
Rep Power: 6
HorstPeter is on a distinguished road
Hi,
you could try to set the pressure outlet boundary to
type fixedValue;
value uniform 0;
Keep the other settings as you posted it here.
ashishmagar600 likes this.
HorstPeter is offline   Reply With Quote

Old   December 15, 2016, 08:24
Default
  #3
New Member
 
Join Date: May 2016
Posts: 25
Rep Power: 6
mgab is on a distinguished road
Found the solution.
The error was that in the output patch both velocity and pressure were set to zeroGradient.
By setting an outlet pressure the solution could be found!
Thanks anyway
mgab is offline   Reply With Quote

Old   December 15, 2016, 08:25
Default
  #4
New Member
 
Join Date: May 2016
Posts: 25
Rep Power: 6
mgab is on a distinguished road
Just found out. Thanks anyway HorstPeter!
mgab is offline   Reply With Quote

Old   April 20, 2017, 23:46
Default Mixing elbow
  #5
New Member
 
Farshad
Join Date: Apr 2017
Posts: 2
Rep Power: 0
Farshad rahimitabar is on a distinguished road
Hello

I am new comer to open Foam. could you please somebody help me for this alarm.

--> FOAM FATAL IO ERROR:
keyword inletValue is undefined in dictionary "/home/farshad/Desktop/elbow/0/k.boundaryField.pressure-outlet-7"

file: /home/farshad/Desktop/elbow/0/k.boundaryField.pressure-outlet-7 from line 35 to line 36.

From function dictionary::lookupEntry(const word&, bool, bool) const
in file db/dictionary/dictionary.C at line 402.

FOAM exiting
Farshad rahimitabar is offline   Reply With Quote

Old   April 25, 2017, 10:47
Default
  #6
New Member
 
Join Date: May 2016
Posts: 25
Rep Power: 6
mgab is on a distinguished road
This alarm says that you haven't defined a value for k.
This might be a better thread for you:
turbulentIntensityKineticEnergyInlet boundary condition
mgab is offline   Reply With Quote

Old   October 10, 2019, 04:29
Default BC for Outlet
  #7
New Member
 
Mohamed Bennour
Join Date: Sep 2019
Posts: 5
Rep Power: 3
mbennour is on a distinguished road
Quote:
Originally Posted by mgab View Post
Found the solution.
The error was that in the output patch both velocity and pressure were set to zeroGradient.
By setting an outlet pressure the solution could be found!
Thanks anyway

hi

how did you set your BC for outlet I become the same error message but I couldn't fix it
thx for your help
mbennour is offline   Reply With Quote

Reply

Tags
boundaries condition, boundary, outflow bc, potentialfoam

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
problem during mpi in server: expected Scalar, found on line 0 the word 'nan' muth OpenFOAM Running, Solving & CFD 3 August 27, 2018 04:18
error with reactingFoam BakedAlmonds OpenFOAM Running, Solving & CFD 4 June 22, 2016 02:21
potentialFoam doesnt start?! Sway OpenFOAM Running, Solving & CFD 0 July 2, 2015 07:48
[blockMesh] Axisymmetrical mesh Rasmus Gjesing (Gjesing) OpenFOAM Meshing & Mesh Conversion 10 April 2, 2007 14:00
[Gmsh] Import gmsh msh to Foam adorean OpenFOAM Meshing & Mesh Conversion 24 April 27, 2005 08:19


All times are GMT -4. The time now is 15:45.