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Modulating Light Source

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I'm trying to model a modulating point source of light in a homogenous scattering and absorbing media. I'm using the coefficient form of the PDE equation. When I enter the time varying equation (sin(omega*t)) for the source into the point setting weak term, there's no photon diffusion into the media. When I enter the equation into the source term of the PDE subdomain setting, the photons appear to propagate, however, the concentration of photons at any two points are perfectly in phase (there should be a time delay between two points as the photons diffuse in time).

I thought the source term in the subdomain was for sources scattered throughout in the media.

Can anyone help clarify what's going on?

Thanks,
Dan

1 Reply Last Post 20 ago 2010, 02:15 GMT-4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 20 ago 2010, 02:15 GMT-4
Hi

I hope you are aware that if you have a harmonic source term you can (mostly depends on the physics/application mod) use the harmonic development of the model, and you do not need to set up a full time transient analysis, it also much quicker (when possible)

I know I'm not really answering your question, because I'm not sure what to answer, neither if I have fully understood it ;)

--
Good luck
Ivar
Hi I hope you are aware that if you have a harmonic source term you can (mostly depends on the physics/application mod) use the harmonic development of the model, and you do not need to set up a full time transient analysis, it also much quicker (when possible) I know I'm not really answering your question, because I'm not sure what to answer, neither if I have fully understood it ;) -- Good luck Ivar

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