Two velocity files generated in each time step U and U_0..Why?
 

Hello all
I am using buoyantboussinesqPimpleFoam.
While running it without any modification in each time directory I have 1 U and 1T file

But after adding some probes at 4 points (always active) and field average (not active most time) in control dict there are
1 U 1U_0 1T and 1T_0 file generated. From manual comaprison I find U and U_0 to be the same and just occupying 2*space.

Is it any issue , or is there any reason for generation of these extra files in each time directory.

Hope the changes I made in controldict (no other changes made) is the probable reason for the generation of files:


------------------------------------------------------------------------------------
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2.3.0 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
location "system";
object controlDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

libs (
"libOpenFOAM.so"
"libsimpleSwakFunctionObjects.so"
"libswakFunctionObjects.so"
"libgroovyBC.so"
);


application DNSbuoyantBoussinesqPimpleFoam;

startFrom latestTime;

startTime 0;

stopAt endTime;

endTime 20060;

deltaT .02;

writeControl timeStep;

writeInterval 10;

purgeWrite 0;

writeFormat ascii;

writePrecision 6;

writeCompression off;

timeFormat general;

timePrecision 6;

runTimeModifiable true;

adjustTimeStep yes;

maxCo 0.4;


functions
(
fieldAverage1
{

type fieldAverage;
functionObjectLibs ("libfieldFunctionObjects.so");
enabled true;
timeStart 20020;
timeEnd 20060;
outputControl timeStep;
writeInterval 10;


fields
(
U
{
mean on;
prime2Mean on;
base time;
}
p
{
mean on;
prime2Mean on;
base time;
}
);
}





NusseltNumber_hot
{
type patchExpression;
outputControl timeStep;
outputInterval 1;
patches (
w_l
);
verbose true;
variables (
"Tsat=301;"
"ln2D=3.065;" /*length(.08)/k(.0261) */
);
expression "ln2D*snGrad(T)/(T-Tsat)";
accumulations (
average
);
}

NusseltNumber_cold
{
type patchExpression;
outputControl timeStep;
outputInterval 1;

patches (
w_r
);
verbose true;
variables (
"Tsat=301;"
"k2D2=3.065;"
);
expression "-1*k2D2*snGrad(T)/(T-Tsat)";

accumulations (
average
);
}






probes1
{
// Type of functionObject
type probes;

outputControl timeStep;
outputInterval 1;

// Where to load it from (if not already in solver)
functionObjectLibs ("libsampling.so");

// Locations to be probed. runTime modifiable!
probeLocations
(
(0.0014 0.0019 0.0)
(.04 .04 0.0)
(.078 .05 0.0)
(.0611 .0775 0.0)
(.079 .062 0.0)
(.06 .023 0.0)
(.022 .058 0.0)
);

// Fields to be probed. runTime modifiable!
fields
(
p
U
T
);
}

);


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

-------------------------------------------------------------------------------------