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How to use if statement in openFoam solver?

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Old   June 24, 2015, 07:53
Default How to use if statement in openFoam solver?
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Hesam
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Hi friends,

I want to add if statement to openfoam solver :

if (Re > 1000)
{
CD=24/Re;
}

else
{
CD=0.44;
}

But I can't implement it!!!

error is :

calcVdj.H: In function ‘int main(int, char**)’:
calcVdj.H:30:21: error: no match for ‘operator>’ in ‘Re > 1.0e+3’
calcVdj.H:30:21: note: candidates are:
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Old   June 29, 2015, 10:25
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Daniel Witte
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This is not very detailed, but maybe you have a type problem. Re must be e.g. of type scalar.

You can add a line upfront:

scalar Ree = Re;

Replace all your Re by Ree. Look at the compilation error. Openfoam will tell of which type Re is (e.g. it has dimensions).

Regards,

Daniel
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Old   July 14, 2015, 09:57
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Bruno Blais
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Quote:
Originally Posted by rapierrz View Post
Hi friends,

I want to add if statement to openfoam solver :

if (Re > 1000)
{
CD=24/Re;
}

else
{
CD=0.44;
}

But I can't implement it!!!

error is :

calcVdj.H: In function ‘int main(int, char**)’:
calcVdj.H:30:21: error: no match for ‘operator>’ in ‘Re > 1.0e+3’
calcVdj.H:30:21: note: candidates are:

As the variable Re been defined as a scalar (or at least a double?) It is not a per-default variable of the solver so you need to define it. The operator > is defined for the scalar type...
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Old   July 14, 2015, 12:26
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Hesam
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Quote:
Originally Posted by blais.bruno View Post
As the variable Re been defined as a scalar (or at least a double?) It is not a per-default variable of the solver so you need to define it. The operator > is defined for the scalar type...
Hi Bruno.I define Re number as scalar.I want to know how i can use if or while statement.

thank you.
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Old   July 14, 2015, 13:51
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Pete Bachant
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You should post more context, i.e. where Re and CD are initialized.
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Old   August 3, 2015, 13:26
Post how to assign a vlue of a variable to each cell
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AJAY BHANDARI
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Hi all,

I am new to open Foam.I have the a problem same as discussed above . i want to use a for loop to assign a variable value to each cell in my mesh . How can i do it??? and where i have to create this loop. any help will be appreciated.

Regards
Ajay
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Old   August 4, 2015, 06:15
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Daniel Witte
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Here just some code lines, how you can do it. You will find it preat all over the code:

Code:
    forAll(owner, facei)
    {
        ssf[facei] =
            deltaCoeffs[facei]*(vf[neighbour[facei]] - vf[owner[facei]]);
    }
The forAll statement is very useful. It automatically determines the size of the vector (owner), the loop variable (facei). The square bracket assignes the individual row value.

This will not work in some part of the code, e.g. in matrix solvers, but elsewhere it does.

Regards,

Daniel
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Old   August 4, 2015, 06:19
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AJAY BHANDARI
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Hi danny,

First of all thanks for your quick reply. I will try what u have said. Can u tell me what is meant by this line it will not work in matrix solvers. I am working in porousSimpleFoam and basically i want to assign porosity to each cell in mesh.

Regards
Ajay
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