[hariya03]

Hi everyone,

I have working with a simpleFoam case to see the flow of air from a inlet to outlet on a specified path.

The mesh has readed from a third party client and boundary patches are set in constant/polymesh.
The control dictionary were set to read for 300 as end time with a write interval of 100.

The fvsolution &t the intial boundary conditions
are feeded.

When I running the '0' time folder for simpleFoam

I got the following error
Application started with pid 22270
/*---------------------------------------------------------------------------*\
| ========= | |
| \ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \ / O peration | Version: 1.4.1 |
| \ / A nd | Web: http://www.openfoam.org |
| \/ M anipulation | |
\*---------------------------------------------------------------------------*/

Exec : simpleFoam /home/harikr/OpenFOAM/harikr-1.4.1/run/tutorials/simpleFoam smartvalve12
Date : Jul 11 2008
Time : 16:48:44
Host : D6
PID : 22270
Root : /home/harikr/OpenFOAM/harikr-1.4.1/run/tutorials/simpleFoam
Case : smartvalve12
Nprocs : 1
Create time

Create mesh for time = 0

Reading field p

Reading field U



--> FOAM FATAL IO ERROR : size 1 is not equal to the given value of 26776

file: /home/harikr/OpenFOAM/harikr-1.4.1/run/tutorials/simpleFoam/smartvalve12/0/U from line 28 to line 229.

From function Field<type>::Field(const word& keyword, const dictionary& dict, const label s)
in file /home/dm2/henry/OpenFOAM/OpenFOAM-1.4.1/src/OpenFOAM/lnInclude/Field.C at line 224.

FOAM exiting

Kindly advice me where i did wrong
If you need any further information, kindly ask me.

Thank you,

V.Hari

[wenterodt]

Dear Hari,

the crucial lines of the error message are:

--> FOAM FATAL IO ERROR : size 1 is not equal to the given value of 26776

file: /home/harikr/OpenFOAM/harikr-1.4.1/run/tutorials/simpleFoam/smartvalve12/0/U from line 28 to line 229.

This means that you have to take a look at line 28 of the U-file, maybe something that should be a vector (size 26776) is defined as a scalar (size 1) or vice versa...

If you can't see it, paste the U-file here.

Regards,

Tammo

[hariya03]

Dear Mr.Tammo,

Thank you for the help..
I hereby pasting the U file. Kindly have a look.
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \ / O peration | Version: 1.4.1 |
| \ / A nd | Web: http://www.openfoam.org |
| \/ M anipulation | |
\*---------------------------------------------------------------------------*/

// Field Dictionary

FoamFile
{
version 2.0;
format ascii;

root "/home/harikr/OpenFOAM/harikr-1.4.1/run/tutorials/simpleFoam";
case "smart12";
instance "0";
local "";

class volVectorField;
object U;
}

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //


dimensions [0 1 -1 0 0 0 0];

internalField nonuniform
(
(0 0 0)
);

boundaryField
{
defaultFaces
{
type empty;
}

inlet
{
type zeroGradient;
}

auto1
{
type fixedValue;
value uniform (0 0 0);
}

auto2
{
type fixedValue;
value uniform (0 0 0);
}

auto3
{
type fixedValue;
value uniform (0 0 0);
}

auto4
{
type fixedValue;
value uniform (0 0 0);
}

auto5
{
type fixedValue;
value uniform (0 0 0);
}

auto6
{
type fixedValue;
value uniform (0 0 0);
}

auto7
{
type fixedValue;
value uniform (0 0 0);
}

auto8
{
type fixedValue;
value uniform (0 0 0);
}

auto9
{
type fixedValue;
value uniform (0 0 0);
}

auto10
{
type fixedValue;
value uniform (0 0 0);
}

auto11
{
type fixedValue;
value uniform (0 0 0);
}

auto12
{
type fixedValue;
value uniform (0 0 0);
}

auto13
{
type fixedValue;
value uniform (0 0 0);
}

auto14
{
type fixedValue;
value uniform (0 0 0);
}

auto15
{
type fixedValue;
value uniform (0 0 0);
}

auto16
{
type fixedValue;
value uniform (0 0 0);
}

auto17
{
type fixedValue;
value uniform (0 0 0);
}

auto18
{
type fixedValue;
value uniform (0 0 0);
}

auto19
{
type fixedValue;
value uniform (0 0 0);
}

auto20
{
type fixedValue;
value uniform (0 0 0);
}

auto21
{
type fixedValue;
value uniform (0 0 0);
}

auto22
{
type fixedValue;
value uniform (0 0 0);
}

auto23
{
type fixedValue;
value uniform (0 0 0);
}

auto24
{
type fixedValue;
value uniform (0 0 0);
}

auto25
{
type fixedValue;
value uniform (0 0 0);
}

auto26
{
type fixedValue;
value uniform (0 0 0);
}

auto27
{
type fixedValue;
value uniform (0 0 0);
}

auto28
{
type fixedValue;
value uniform (0 0 0);
}

auto29
{
type fixedValue;
value uniform (0 0 0);
}

auto30
{
type fixedValue;
value uniform (0 0 0);
}

outlet
{
type zeroGradient;
}
}


// ************************************************** *********************** //

[wenterodt]

with the line

internalField nonuniform

you tell the solver that the field is not uniform upon start, but then you prescribe (0 0 0) for the entire field, i.e. uniform. What you have to do is simply change "internalField nonuniform" to "internalField uniform"

Good luck,

Tammo

[hariya03]

Dear Mr.Tammo,

Thank you again for your clarification.

Could you also advice me if the U field is to be non uniform, which data is to modified?

Thank you,

V.Hari.

[wenterodt]

The best way to figure this out is to run some of the tutorials (as described in the UserGuide) and then have a look at the U-files for timesteps after 0. Its pretty self-explanatory.

To initialize the field with something half reasonable, you may wish to run potentialFoam first (also see UserGuide).

Best wishes,

Tammo

[hariya03]

Dear Mr.Tammo,

Thank you very much for your reply.

I did it with uniform conditions itself.

I had seen user guide for many of my doubts. Its very brief as I look in OpenFOAM site.

I need another one basic clarification to know how to read the iteration results and what does the residuals actually mean.

We are calculating the flow rate of a valve.

In inlet 7000 Pa is given and outlet is 0Pa and we fixed outlet pressurised condition to both inlet and outlet.

after running the simple foam i am getting these results.


Time = 1

DILUPBiCG: Solving for Ux, Initial residual = 1, Final residual = 1.49213e-05, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCG: Solving for Uz, Initial residual = 0, Final residual = 0, No Iterations 0
GAMG: Solving for p, Initial residual = 1, Final residual = 0.000601879, No Iterations 6
time step continuity errors : sum local = 2.18714, global = -0.0619567, cumulative = -0.0619567
DILUPBiCG: Solving for epsilon, Initial residual = 0.897335, Final residual = 1.02147e-05, No Iterations 1
DILUPBiCG: Solving for k, Initial residual = 1, Final residual = 1.38556e-05, No Iterations 1
ExecutionTime = 0.77 s ClockTime = 1 s

Time = 2

DILUPBiCG: Solving for Ux, Initial residual = 0.00335051, Final residual = 4.38432e-08, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 0.00397104, Final residual = 4.84344e-08, No Iterations 1
DILUPBiCG: Solving for Uz, Initial residual = 0.00331844, Final residual = 4.17761e-08, No Iterations 1
GAMG: Solving for p, Initial residual = 0.943068, Final residual = 0.000466685, No Iterations 14
time step continuity errors : sum local = 0.500458, global = -0.060284, cumulative = -0.122241
DILUPBiCG: Solving for epsilon, Initial residual = 0.862161, Final residual = 1.21649e-05, No Iterations 1
DILUPBiCG: Solving for k, Initial residual = 0.842201, Final residual = 1.88649e-05, No Iterations 1
ExecutionTime = 1.24 s ClockTime = 1 s

Time = 3

DILUPBiCG: Solving for Ux, Initial residual = 0.147196, Final residual = 2.8822e-06, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 0.112165, Final residual = 1.96374e-06, No Iterations 1
DILUPBiCG: Solving for Uz, Initial residual = 0.138183, Final residual = 2.76485e-06, No Iterations 1
GAMG: Solving for p, Initial residual = 0.631318, Final residual = 0.000284522, No Iterations 6
time step continuity errors : sum local = 2.06408, global = -0.124974, cumulative = -0.247215
DILUPBiCG: Solving for epsilon, Initial residual = 0.863321, Final residual = 1.39978e-05, No Iterations 1
DILUPBiCG: Solving for k, Initial residual = 0.813142, Final residual = 2.10478e-05, No Iterations 1
ExecutionTime = 1.62 s ClockTime = 1 s


I did the iteration to 300 time and input the 300 time to 0th time,

Could you educate me about the basic questions below?
what does this paragraph mean?

What to calculate actually from this paragraph?

What for the residuals stand and how to interpret the values from it?


I could not found out the details in users manual.

it would be helpful for me if you advice the regard.

Thank you

V.Hari