Hi,

I've written an UDF to direcly link the material density to it's temperature. It is supposed to be an laminair incompressible fluid. When I display the temperature and the densisty, to my knowledge these two should be identical. But although they look almost the same they are not a perfect match.

My guess is Fluent is modeling it like a compressible fluid, hence the small densisty differences.

Can you explain to me what I'm overlooking or should change in Fluent?

Regards,

P.

hi , u have seemed to use a UDF in which density is a function of a temperature , right , so u will see some difference in the two plots of temperature and density. R u lookin for natural convection case ? As far as my knowledge is concerned , u cannot comment on a flow ( u have mentioned fluid , did u meant flow ?)compressible or incompressible depending on just density variation with temperature , which i mention is a case of a pure natural convection case , where the flow is still modelled as incompressible

I think fluent is correct in its representation as far as u r lookin for convection case, let me what u think of

regards pratik