[saifee]

I'm using OpenFOAM 10. Following is a portion of a p boundary condition for a particular patch in the domain. I'm trying to achieve a sinusoidal pressure evolution, meaning the flow will be changing direction over the period. Is the following correct for a 3 second period? The reason I'm asking is because in the results, if I look at some p file, the frequency shows to be 2.

    {
	type		uniformTotalPressure;
	p0
	{
		type		sine;
		frequency	2.0*pi/3.0;
		amplitude	-50.0;
		//scale		-1;
		level		0;
	}


    }

Whereas in some p file from the results, it shows

    {
        type            uniformTotalPressure;
        rho             rho;
        psi             none;
        gamma           1;
        p0              
        {
            type            sine;
            amplitude       
            {
                type            constant;
                value           -50;
            }
            frequency       2;
            start           0;
            level           
            {
                type            constant;
                value           0;
            }
        }
        value           uniform -12.4322;
    }

[Alczem]

Hey!


Not sure about formulas directly written in place of a number, although you could use eval to compute your frequency or any variable beforehand. So for instance, you would write before the boundary subdictionary:

freq     #eval {2*pi/3};




{
    type        uniformTotalPressure;
    p0
    {
        type        sine;
        frequency    $freq;
        amplitude    -50.0;
        //scale        -1;
        level        0;
    }
}

And of course, you can use variables inside variables (dont forget the $ sign when calling other variables). Hope it helps! There is probably a way to do this inside the boundary condition but I am not sure how (maybe codedStream?).

[saifee]

Thanks for the response.

Where should I put this eval function? Not in the p file?

[saifee]

Originally Posted by Alczem

Hey!


Not sure about formulas directly written in place of a number, although you could use eval to compute your frequency or any variable beforehand. So for instance, you would write before the boundary subdictionary:

freq     #eval {2*pi/3};




{
    type        uniformTotalPressure;
    p0
    {
        type        sine;
        frequency    $freq;
        amplitude    -50.0;
        //scale        -1;
        level        0;
    }
}

And of course, you can use variables inside variables (dont forget the $ sign when calling other variables). Hope it helps! There is probably a way to do this inside the boundary condition but I am not sure how (maybe codedStream?).

I put the freq #eval {2*pi/3}; in the p file before the boundaryField subdictionary. I received the error:

--> FOAM FATAL ERROR:
Unknown functionEntry 'eval' in ".../0/p" near line 21

Valid functionEntries are :

6
(
codeStream
include
neg
calc
includeIfPresent
includeEtc
)

Then I used calc from the list, which then gave me this error:

--> FOAM FATAL IO ERROR:
Failed wmake "dynamicCode/_6d73af34a7a2711a081b60b9b371eecacacd3dbd/platforms/linux64GccDPInt32-spack/lib/libcodeStream_6d73af34a7a2711a081b60b9b371eecacacd 3dbd.so"

Now I am running the simulation on a mainframe, so I don't have the write access to certain directories, just mine.

So is there a way to use some different approach?

[Alczem]

Hey!


Okay that's weird. I noticed that you use OpenFOAM 10 while I use OpenFOAM v2312, maybe the eval feature is not available for the Foundation version.


The calc function seems to need to compile stuff, since there is a dynamicCode folder and a wmake command sent. To make sure the error is not related to access privileges, you could try to run a test case locally on your computer if you can.