[Manouu]

Hi Openfoamers, I published my problem on the forum a few days ago but I did not receive any help. I want to explain more my case, I am working on laminar flow in a cylindrical tube using simpleFoam solver. I use water as a fluid, in my experimental work, I applied an ultrasonic wave to the flow of the fluid in the tube, this wave will generate a volumetric force which will influence the speed of the flow. I calculated the values ​​of this force in each points of my mesh using a matlab code and I would now like to introduce only a value of this force in its point in openfoam as a constant source term in the z direction in order to study its effect on flow velocity. I am beginner on openfoam and I know that fvOptions allows me to add uniform source term which depends on position and according to UserGuide on codedSource I try to create the code below and use vectorCodedSource, the code it works but the solution doesn't converge and the results don't make sense, I reach huge speed values. how can I correct my code please? The force unit is m.s-2 (F/rho*Volume), I want to know how I can set the force unit in the code? I use openFoam 4.1
I hope to find help
regards

volumetricForce
{
type vectorCodedSource;
active on;
name volumetricForce;

vectorCodedSourceCoeffs
{
fields (U);

selectionMode points;
points
(
(0 0 0)
);


codeInclude
#{

#};

codeCorrect
#{
Pout<< "**codeCorrect**" << endl;
#};

codeAddSup
#{
vectorField& USource = eqn.source();
const scalarField& V = mesh_.V();
vector const F (0,0,0.804);
USource -= F;
#};

codeSetValue
#{
Pout<< "**codeSetValue**" << endl;
#};

code
#{
$codeInclude
$codeCorrect
$codeAddSup
$codeSetValue
#};
}

sourceTimeCoeffs
{
}

[Mahmoud Abbaszadeh]

Originally Posted by Manouu

Hi Openfoamers, I published my problem on the forum a few days ago but I did not receive any help. I want to explain more my case, I am working on laminar flow in a cylindrical tube using simpleFoam solver. I use water as a fluid, in my experimental work, I applied an ultrasonic wave to the flow of the fluid in the tube, this wave will generate a volumetric force which will influence the speed of the flow. I calculated the values ​​of this force in each points of my mesh using a matlab code and I would now like to introduce only a value of this force in its point in openfoam as a constant source term in the z direction in order to study its effect on flow velocity. I am beginner on openfoam and I know that fvOptions allows me to add uniform source term which depends on position and according to UserGuide on codedSource I try to create the code below and use vectorCodedSource, the code it works but the solution doesn't converge and the results don't make sense, I reach huge speed values. how can I correct my code please? The force unit is m.s-2 (F/rho*Volume), I want to know how I can set the force unit in the code? I use openFoam 4.1
I hope to find help
regards

volumetricForce
{
type vectorCodedSource;
active on;
name volumetricForce;

vectorCodedSourceCoeffs
{
fields (U);

selectionMode points;
points
(
(0 0 0)
);


codeInclude
#{

#};

codeCorrect
#{
Pout<< "**codeCorrect**" << endl;
#};

codeAddSup
#{
vectorField& USource = eqn.source();
const scalarField& V = mesh_.V();
vector const F (0,0,0.804);
USource -= F;
#};

codeSetValue
#{
Pout<< "**codeSetValue**" << endl;
#};

code
#{
$codeInclude
$codeCorrect
$codeAddSup
$codeSetValue
#};
}

sourceTimeCoeffs
{
}

are you going to add the F values to all cells, like gravity, or just a specific cell?

[olesen]

The soon-to-been-released OpenFOAM-v2206 will support volume expressions for source terms, which means that you should be able to shape the selection a bit more precisely.
Otherwise you will probably need to preselect cells as a cellSet and restrict your sources to them.