Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

Parameters from heat transfert to Poisson's equation

Please login with a confirmed email address before reporting spam

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.

1 Reply Last Post 29 juin 2010, 13:37 UTC−4

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 29 juin 2010, 13:37 UTC−4
Problem solved.
Problem solved.

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.