[edbarino]

Hi all,

I am trying to work out how to solve the spectral irradiance within a vessel with a light source on a boundary. I am wondering how I could adapt the hotRadiationRoomFvDOM case in the tutorials/heatTransfer/buoyantSimpleFoam directory to include the spectral irradiance.

So far, I know I need as a boundary condition for my radiative source;
wideBandDiffusiveRadiation


I need to know how I can use this boundary condition to set several discrete bands of photons (not phonons - temperature is not important for the minute) (namely 500-540 nm, 790-820 nm, 830-900 nm), preferably normally distributed (to reflect the distribution of the LED output). I have so far found;


nLambda (number of wavelength bands) - 3 in my case
nRay (number of rays)
aLambda (spectral absorption coeff) - 3 of them

IRayLambda spectral intensity of ray
lambdaI spectral irradiance
rayI irradiance of ray
setRayLambdaId ??
rayId ??
lambdaId ??

I would like to know in which dictionaries and directories I need to place all of these parameters. I am assuming nLambda, nRay, aLambda go within the constant/radiationProperties file with the other fvDOMCoeffs. Do I need to put the others in the 0 directory as an initial condition?

I basically know what I'm doing in terms of the physics, but it is frustrating not to be able to implement this in OF due to the lack of knowledge of how to set it up. This is the last piece of the puzzle for my model.

Thanks in advance for your help,

Ed

[esujby]

i think what you need is IDefault file on the 0 directory, which sets the place holders for calculating all those. you should have a look at how other cases are set up, run them and understand the parameters used. then solving your case afterward there....

this is a goos starting point

https://github.com/OpenFOAM/OpenFOAM...eaterRadiation

[zfaraday]

Originally Posted by edbarino

Hi all,

I am trying to work out how to solve the spectral irradiance within a vessel with a light source on a boundary. I am wondering how I could adapt the hotRadiationRoomFvDOM case in the tutorials/heatTransfer/buoyantSimpleFoam directory to include the spectral irradiance.

So far, I know I need as a boundary condition for my radiative source;
wideBandDiffusiveRadiation


I need to know how I can use this boundary condition to set several discrete bands of photons (not phonons - temperature is not important for the minute) (namely 500-540 nm, 790-820 nm, 830-900 nm), preferably normally distributed (to reflect the distribution of the LED output). I have so far found;


nLambda (number of wavelength bands) - 3 in my case
nRay (number of rays)
aLambda (spectral absorption coeff) - 3 of them

IRayLambda spectral intensity of ray
lambdaI spectral irradiance
rayI irradiance of ray
setRayLambdaId ??
rayId ??
lambdaId ??

I would like to know in which dictionaries and directories I need to place all of these parameters. I am assuming nLambda, nRay, aLambda go within the constant/radiationProperties file with the other fvDOMCoeffs. Do I need to put the others in the 0 directory as an initial condition?

I basically know what I'm doing in terms of the physics, but it is frustrating not to be able to implement this in OF due to the lack of knowledge of how to set it up. This is the last piece of the puzzle for my model.

Thanks in advance for your help,

Ed

Hi @edbarino,

Did you manage to solve your case with several dicrete wave lenght bands with fvDOM? I am also interested in learning how to solve this kind of problems now.

As far as I could find so far the BC you mention, "wideBandDiffussiveRadiation", is to be used with the "wideBandAbsorptionEmission" submodel which requires a list of species and coefs to describe the emission/absorption of the media (not the boundary surfaces). The problem here is that I am interested (as I understand you also were) in describing the emissivity of the surfaces in a non-participating media. However, I couldn't manage to define non-gray spectral emissivity for the surfaces of my domain.

Can anyone help me to define non-gray spectral emissivity for surfaces using fvDOM? Can wideBandDiffussiveRadiation BC be used in order to do it?

I would be very grateful if somebody could give me a hint with this issue.

Cheers,

Alex

[B_R_Khan]

Originally Posted by zfaraday

Hi @edbarino,

Did you manage to solve your case with several dicrete wave lenght bands with fvDOM? I am also interested in learning how to solve this kind of problems now.

As far as I could find so far the BC you mention, "wideBandDiffussiveRadiation", is to be used with the "wideBandAbsorptionEmission" submodel which requires a list of species and coefs to describe the emission/absorption of the media (not the boundary surfaces). The problem here is that I am interested (as I understand you also were) in describing the emissivity of the surfaces in a non-participating media. However, I couldn't manage to define non-gray spectral emissivity for the surfaces of my domain.

Can anyone help me to define non-gray spectral emissivity for surfaces using fvDOM? Can wideBandDiffussiveRadiation BC be used in order to do it?

I would be very grateful if somebody could give me a hint with this issue.

Cheers,

Alex

Hi!
Did you figure out where to define specific wavelength bands for fvDOM to solve? I don't know where nLambda is defined.

Thanks