convert dimensioned<double>’ to ‘double’
 

cannot convert ‘const Foam::dimensioned<double>’ to ‘double’ in assignment

hi friends i have following code what can i do for above compiling error ?

T[i]=TSat;
T is volscalarfield and Tsat is a dimensioned scalar ,

If you just need the value without the dimensions:
should work.
This method is covered in the doxygen for dimensioned types:
http://foam.sourceforge.net/doc/Doxy...mensioned.html

hey
i'm facing a similar problem while trying to build a new drag model
i need to calcuate Eotvos number (E) which i have defined as a volScalarField.

volScalarField E = Gravity.value()*(phaseb_.rho()-phasea_.rho())*pow(phasea_.d(),2.0)/sigma.value();

i needed to define g and sigma. i am defining them as dimensionedScalars but when i give them in the formula i get an error

Models/SchillerNaumann/SchillerNaumann.C:89: error: conversion from ‘Foam::dimensioned<double>’ to non-scalar type ‘Foam::volScalarField’ requested

Any suggestions how to get over this problem? i tried the variable.value() as suggested above but the error still remains.

thanks.

Pritika

hi paritika
above solution works for me,
whats ur volscalarField variable in the right hand of equation?

hey

there is no volScalarField on the right side of the equation. they are all constants basically. rho (the density) and d (the diameter) are being read form the Phase model( i think as dimensioned scalars itself).
gravity and sigma i have defined as dimensioned scalars.

hi Pritika
so use the following code :
volScalarField E;
forAll (E,celli)
{
E[celli] = Gravity.value()*(phaseb_.rho()-phasea_.rho())*pow(phasea_.d(),2.0)/sigma.value();
}
could you tell me why do u define E as volScalarField ?

hey nima

i need E as a volScalarField as i need to compare it with reynolds number in an if condition and reynolds number is a volscalarField due to velocity.

thanks for the help

hey nima

i tried your suggested code but now i face a new error

error: cannot convert ‘Foam::dimensioned<double>’ to ‘double’ in assignment.

any suggestions? thanks again

If you use the zero-sized volScalarField 'E' as above, you are headed for a segfault.
You need to allocate/dimension it beforehand.

If all of the values are indeed constants, then I'd think you'd use something like this:

You'll need to work a bit on getting the dimensions correct, or else simply define everything to be dimensionless. This is for you to decide.

hey
i tried the above suggested method but i get the following errors

error: ‘runTime’ was not declared in this scope
dragModels/SchillerNaumann/SchillerNaumann.C:94: error: ‘mesh’ was not declared in this scope
dragModels/SchillerNaumann/SchillerNaumann.C:105: error: no matching function for call to ‘Foam::dimensioned<double>::dimensioned(const char [4], Foam::dimensionSet, Foam::dimensioned<double>)’


i have tried something different now, instead of defining E as vol scalar i do the following

dimensionedScalar E
(
"E",
dimensionSet(0,0,0,0,0,0,0),
Gravity.value()*(phaseb_.rho() - phasea_.rho()) * sqr(phasea_.d()) / sigma.value()
);


dimensionedScalar Cd2
(
"Cd2",
dimensionSet(0,0,0,0,0,0,0),
8.0*(E.value()/E.value()+4)/3.0
);
then compare Cd2 as follows

forAll(Re, celli)
{
if(Cds[celli] < Cd2)
{
Cds[celli] = Cd2;
}
}
but i am still find an error

error: no matching function for call to ‘Foam::dimensioned<double>::dimensioned(const char [2], Foam::dimensionSet, Foam::dimensioned<double>)’

any suggestions on this one?

Hello all,

I have the following piece of code that I wrote for a boundary condition.
When i compile it I get the following ---> "error: cannot convert ‘Foam::tmp<Foam::Field<double> >’ to ‘Foam::scalar {aka double}’ in initialization.

Can you tell me where I'm going wrong. Apologies if it is a basic mistake.

Greetings Srivaths,

I can't figure out in which line that error is occurring. To which line is that message referring to?

In addition, of what kind is the variable "scalarCoeff_"?

Best regards,
Bruno

Hi Bruno,

Apologies, my bad! The error comes in the line where i assign Ux = scalarCoeff_*x[patchi].
And scalarCoeff is a ratio of two scalars that is to be given as input.

In this BC, i'm trying to re-define the expression for refGradient with the vectorField 'modGrad'. I want to assign the first component of refGrad as the scalarCoeff_*(x-value of the face centre of each patch) on which this BC is applied.

Am i making a basic mistake of assigning a scalarField to a scalar?

Hi Srivaths,

If I'm not mistaken, I saw this just this past Friday. You're missing the forAll loop for the faces inside the patch.

Let me see if I can find a piece of OpenFOAM code that does this... after a very quick search, have look into the file "src/finiteVolume/fields/fvPatchFields/derived/supersonicFreestream/supersonicFreestreamFvPatchVectorField.C" and/or look for other files that use the variable "facei".

Best regards,
Bruno

That was a quick reply. Thank you Bruno! I'll have a look at that BC.

Dear Sherlock,
did you get through your problem?
I am getting an error similar to one of yours,
"cannot convert 'Foam::tmp<Foam::GeometricField<Foam::vector<doubl e>,Foam::fvPatchField,Foam::volMesh>>' to 'int' in return"
Please see whether somwone can help me......:)

Thanks in advance

It means that your function is returning the wrong type. Without code, it is difficult to say anything else.

what I wanted is to create an anisotropic thermal conductivity field using 2volScalarFields and zero("0") for other direction.
my code is as follows(followed fromheSolidThermo.C)
I tried 2 methods and neither of them worked.
document is attaching.
Method 1: is from line 800-892(which gives mentioned error)
Method 2: is from line 762-798
2 volScalarFields are calculated using the equation k=(ko+.5*Re*Pr) and (ko+0.1*Re*Pr)

Thanks

although any of the 2 methods did not work.I managed to do that in following manner.(still I have to give BCs using 0 folder)
((ko ko 0)+(.1 .5 0)*Pr*Re)
I think OF does not let generating a vectorField using 2 or 3 scalarfields as I have tried in earlier document attached.so,I used vector fields to generate the same.
"wmake" is running but dont know what will arise when running the case file.
However I would like to know your opinions on my early effort and this one too.

Dear Foamers,
 

I am stucked with an error for some days and could not manage to solve it.As I mentioned earlier in my post.I resolved making the volVectorField.But this time it seems difficult to solve this without a help.
my error after runnign wmake is as follows.Please try to help.


Thanks.