[b.simpson]

Hi,

I am setting up a natural ventilation model using buoyantBoussinesqSimpleFoam in OpenFOAM-v1812. The model is currently a very simple box shaped room with a window on either side.

My current task is to calculate/predict the air velocity and the total CO2 concentration passing through the windows into the room and also leaving the room.

Could someone inform me of the method I should be using to accomplish this?

I am happy to provide more information regarding my model set-up if needed.

Thank you for any advise you can provide.

Kind regards,
Ben

[Linea]

Hi, I just saw your post and was wondering if you got any further on the implementation of CO2 in your model? I have to simulate natural ventilation as well and I am struggling with impleneting the CO2 relase of a person into the room.

Any help is really appreciated.

[b.simpson]

Hi Marlen,

I have CO2 implemented into my natural ventilation model. I did this by adding CO2 into the thermophysicalProperties file in the constant folder.

CO2
{
    specie
    {
        molWeight       44.01;
    }
    thermodynamics
    {
        Tlow            200;
        Thigh           5000;
        Tcommon         1000;
        highCpCoeffs    ( 4.45362 0.00314017 -1.27841e-06 2.394e-10 -1.66903e-14 -48967 -0.955396 );
        lowCpCoeffs     ( 2.27572 0.00992207 -1.04091e-05 6.86669e-09 -2.11728e-12 -48373.1 10.1885 );
    }
    transport
    {
        As              1.67212e-06;
        Ts              170.672;
    }
}

I need to sense check the thermodynamics and transport values.

I created an inlet object at the surface of my person object. I set a CO2 concentration in a CO2 file in the 0 folder and set an air velocity in the U file.

In the controlDict file I added a CO2 function in the functions section.

CO2
		{
			type    			scalarTransport;
			libs 				("libsolverFunctionObjects.so");
			writeControl       	timeStep;
			writeInterval      	1;
			active          	true;
			autoSchemes     	false;
			nCorr           	0;
			resetOnStartUp 		false;
			field				CO2;
			fvOptions       
			{
			 
			}
		}

I haven't validated my model yet so I cannot be 100% sure that this is working as expected.

Hopefully that helps.

Regards,
Ben