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Parameters from heat transfert to Poisson's equation
Posted Jun 28, 2010, 4:59 p.m. EDT 1 Reply
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Hi,
so I am modeling some heat transfert in solid, in v4.0.
I am working in stationary so I wanted to set the same model with Poisson's equations instead of heat transfert, which should be pretty much the same thing.
I set up the model but when I am solving I don't get the same dispersion. It seems my problem comes from the thermal diffusivity.
Basicaly I have some air trapped between 2 different layers of insulant, with a cold source and a hot source.
I found and verified on my own that the thermal diffusivity of the air is around 2e-5 m²/s. The thermal diffusivities of my insulants are around xe-7. But somehow with those numbers I get a diffusion too fast in the air. When I change the value of the air diffusivity around 2e-7, I get the expected dispersion.
I used the parameters of my heat transfert model to calculate the thermal diffusivities, so I must be missing something somewhere, I have a a hard time believing that's just a parameter issue, especially when I checked them several times.
Could it be because I am working a 2D model with 3D parameters ?
Thank you.
so I am modeling some heat transfert in solid, in v4.0.
I am working in stationary so I wanted to set the same model with Poisson's equations instead of heat transfert, which should be pretty much the same thing.
I set up the model but when I am solving I don't get the same dispersion. It seems my problem comes from the thermal diffusivity.
Basicaly I have some air trapped between 2 different layers of insulant, with a cold source and a hot source.
I found and verified on my own that the thermal diffusivity of the air is around 2e-5 m²/s. The thermal diffusivities of my insulants are around xe-7. But somehow with those numbers I get a diffusion too fast in the air. When I change the value of the air diffusivity around 2e-7, I get the expected dispersion.
I used the parameters of my heat transfert model to calculate the thermal diffusivities, so I must be missing something somewhere, I have a a hard time believing that's just a parameter issue, especially when I checked them several times.
Could it be because I am working a 2D model with 3D parameters ?
Thank you.
1 Reply Last Post Jun 29, 2010, 1:37 p.m. EDT
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Posted:
1 decade ago
Problem solved.