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 Dimon June 29, 2011 03:47

Combination of simple Photometric and CFD analysis

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Brief description of a problem.
I have very simple chemical reactor with water flow lighted by flash lamps. (see pic.). There is numerous of small bodies inside the flow. I'm modeling energy absorbed (doze) by this bodies during passing the reactor. My task is to improve geometry of the reactor to increase the doze.

I ask for advice for modeling the light source. During modelling I find very strange result for doze, there was no big difference how far from the light source small body is. I have create simple model (pic 2) several spheres one of them was source of radiation. I see all the spheres absorb equal energy, but the distance between them was different.

I use Discrete Transfer model. Radiation source is isotropic. Absorption is measured by using Absorbed Radiation Flux function.

 ghorrocks June 29, 2011 06:45

If the outer wall is reflective then the radiation will be uniform and no matter where it is it will get the same dose. What is your outer wall boundary condition for radiation?

 Dimon June 29, 2011 08:35

Boundary condition for wall:
Wall Emissivity - 0
Diffuse fraction - 1

But in my second model (pic.2) I expected to see inverse-square law, because there is no any walls except spheres, all others was opening(material - air).

 ghorrocks June 29, 2011 08:44

But what radiation condition did you apply to the opening? I think you want to apply 0K blackbody temp so no radiation comes back from the opening.

 Dimon June 29, 2011 09:11

Thank you for idea with blackbody temperature at the opening, I've forgot about it.

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