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Reaction rate depending on the temperature field

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Old   January 9, 2014, 05:48
Default Reaction rate depending on the temperature field
  #1
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Thamali
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Hi all,
I am trying to apply a reaction rate depending on the temperature of the solid phase for my new solver.
After runnig "wmake" it shows some errors.Can someone help me on finding the error.
my code is to calculate the "dryingRate" depending on the temperature.
  • when temperature(ts)<373K
dryingRate=scalar(6)*massTransCoeff*(Ymoist*rhos]-YH2O*rho)/F;

  • when temperature =373K
dryingRate=scalar(6)*(convectiveHeatTransCoeff *(tg -ts)+scalar(0.9)*stephBoltz*(pow(298.15,4)-pow(ts ,4)))/(F*VapHeat);
  • when temperature >373K
dryingRate=0

my code is as follows,

forAll(ts,celli) //ts is a volScalarField
{
if(ts[celli]<hunderdCel.value()) //this is 373K
{dimensionedScalar dryingRate[celli]=scalar(6)*massTransCoeff[celli]*(Ymoist[celli]*rhos[celli]-YH2O[celli]*rho)/F;
//return dryingRate[celli];
}
else if(ts[celli]=(hunderdCel.value()))
{

dimensionedScalar dryingRate[celli]=scalar(6)*(convectiveHeatTransCoeff[celli] *(tg[celli] -ts[celli] )+scalar(0.9)*stephBoltz*(pow(298.15,4)-pow(ts[celli] ,4)))/(F*VapHeat);
//return dryingRate[celli];
}
//else(ts[celli]>hunderdCel.value());
else
{dimensionedScalar dryingRate=Zero;}
//return dryingRate[celli];}

}


please see whether can someone find the error.The error is as follows,

createFields.H:1046:115: error: variable-sized object ‘dryingRate’ may not be initialized
{dimensionedScalar dryingRate[celli]=scalar(6)*massTransCoeff[celli]*(Ymoist[celli]*rhos[celli]-YH2O[celli]*rho)/F;
^
createFields.H:1046:21: warning: unused variable ‘dryingRate’ [-Wunused-variable]
{dimensionedScalar dryingRate[celli]=scalar(6)*massTransCoeff[celli]*(Ymoist[celli]*rhos[celli]-YH2O[celli]*rho)/F;
^
createFields.H:1049:40: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
else if(ts[celli]=(hunderdCel.value()))
^
createFields.H:1052:174: error: variable-sized object ‘dryingRate’ may not be initialized
dimensionedScalar dryingRate[celli]=scalar(6)*(convectiveHeatTransCoeff[celli] *(tg[celli] -ts[celli] )+scalar(0.9)*stephBoltz*(pow(298.15,4)-pow(ts[celli] ,4)))/(F*VapHeat);
^
createFields.H:1052:20: warning: unused variable ‘dryingRate’ [-Wunused-variable]
dimensionedScalar dryingRate[celli]=scalar(6)*(convectiveHeatTransCoeff[celli] *(tg[celli] -ts[celli] )+scalar(0.9)*stephBoltz*(pow(298.15,4)-pow(ts[celli] ,4)))/(F*VapHeat);
^

Thanks in advance.

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Old   January 11, 2014, 05:37
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Thamali
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still trying to do the above but not working,I did some amendments to the coding which seemed to me errorneous.
added following internalFields.

scalarField& tgCells =tg.internalField();
//scalarField& dryingRateCells =dryingRate.internalField();
scalarField& massTransCoeffCells =massTransCoeff.internalField();
scalarField& YmoistCells =Ymoist.internalField();
scalarField& rhosCells =rhos.internalField();
scalarField& convectiveHeatTransCoeffCells=convectiveHeatTransC oeff.internalField();
scalarField& tsCells =ts.internalField();
scalarField& YH2OCells=YH2O.internalField();

forAll(tgCells,celli)
{
if (mag(tgCells[celli])<373.15)
{
dimensionedScalar dryingRateCells[celli]=scalar(6)*massTransCoeffCells[celli]*(YmoistCells[celli]*rhosCells[celli]-YH2OCells[celli]*rho)/F;
}
else
{
if (mag(tgCells[celli])==373.15)

dimensionedScalar dryingRateCells[celli]=scalar(6)*(convectiveHeatTransCoeffCells[celli] *(tgCells[celli] -tsCells[celli] )+scalar(0.9)*stephBoltz*(pow(298.15,4)-pow(tsCells[celli] ,4)))/(F*VapHeat);

else

dimensionedScalar dryingRateCells[celli]=Zero;

}
}


But this does not work.Following are the errors.I am struggling to get over with it.

createFields.H:1019:139: error: variable-sized object ‘dryingRateCells’ may not be initialized
dimensionedScalar dryingRateCells[celli]=scalar(6)*massTransCoeffCells[celli]*(YmoistCells[celli]*rhosCells[celli]-YH2OCells[celli]*rho)/F;
^
createFields.H:1019:20: warning: unused variable ‘dryingRateCells’ [-Wunused-variable]
dimensionedScalar dryingRateCells[celli]=scalar(6)*massTransCoeffCells[celli]*(YmoistCells[celli]*rhosCells[celli]-YH2OCells[celli]*rho)/F;
^
createFields.H:1025:201: error: variable-sized object ‘dryingRateCells’ may not be initialized
dimensionedScalar dryingRateCells[celli]=scalar(6)*(convectiveHeatTransCoeffCells[celli] *(tgCells[celli] -tsCells[celli] )+scalar(0.9)*stephBoltz*(pow(298.15,4)-pow(tsCells[celli] ,4)))/(F*VapHeat);
^
createFields.H:1025:22: warning: unused variable ‘dryingRateCells’ [-Wunused-variable]
dimensionedScalar dryingRateCells[celli]=scalar(6)*(convectiveHeatTransCoeffCells[celli] *(tgCells[celli] -tsCells[celli] )+scalar(0.9)*stephBoltz*(pow(298.15,4)-pow(tsCells[celli] ,4)))/(F*VapHeat);
^
createFields.H:1029:45: error: variable-sized object ‘dryingRateCells’ may not be initialized
dimensionedScalar dryingRateCells[celli]=Zero;
^
createFields.H:1029:22: warning: unused variable ‘dryingRateCells’ [-Wunused-variable]
dimensionedScalar dryingRateCells[celli]=Zero;
^
createFields.H:1013:19: warning: unused variable ‘dryingRateCells’ [-Wunused-variable]
dimensionedScalar dryingRateCells[mesh.nCells()];
^


If anyone can see where are the errors come from,I am grateful.
Thanks.

Last edited by Thamali; January 12, 2014 at 00:44. Reason: errors
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Old   January 13, 2014, 06:14
Default Answer
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Thamali
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Even I did not receive any reply.I would like to mention,how I solved this.(I hope this method is correct)
Instead of declaring 373.15 or it as a dimensionedScalar,I declared that too as a volScalarField.And directly compared it with ts,

volScalarField dryingRate =volScalarField::null();
volScalarField dryingRate1=-scalar(6)*massTransCoeff*(Ymoist*rhos-YH2O*rho)/F;
volScalarField dryingRate2=-scalar(6)*(convectiveHeatTransCoeff *(tg -ts)+scalar(0.9)*stephBoltz*(pow(298.15,4)-pow(ts,4)))/(F*VapHeat);
//volScalarField dryingRate3=0;
const volScalarField hundredCel
(
IOobject
(
"hundredCel",
runTime.timeName(),
mesh,
IOobject::NO_READ,
IOobject::NO_WRITE
),
mesh
//dimensionedScalar("zero", dimTemperature, 0.0),
//zeroGradientFvPatchScalarField::typeName
);

if(ts<hundredCel)
dryingRate=dryingRate1;
else
{
if(ts<hundredCel)
dryingRate=dryingRate2;
else
dryingRate=volScalarField::null();
}

If there is any thing wrong in the coding please let me know.
Thamali
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