code_saturne User's Forum

hello!
i actually use code saturne version 3.0.0 and I want to simulate the diffusion of formaldehyde in a flat . it is coupled by air ventilation so i can after evaluate the concentration of the formaldéhyde in the air and see if tthat is higher or lower than 10µg/m3.
But i have serious problem to do that!
i only have the émissions of formaldéhyde its density and diffusion coefficient of the formaldéhyde.
but i can not define to type of fluid using code saturne.
can you help me to model this problem!
how can i settle ia simultion with two phase flows (air and formaldehyde)
Do you have any tutoriel that will help me understand more!

best regards!!

Hello,

You do not "really" need 2 phases, only to add a user "species" for the formaldehyde concentration
(this is possible with the GUI). For finer control, you may define user properties, with a density based on the air + formaldehyde fraction.

There might be some old posts on this forum from users who have similar questions.

Regards,

Yvan

Hello

i establish a program to follow the concentration . could you please tell me if that is going to work using code saturne 3.0.0
the only data that i have are the surface emissions or the mass flow rate, the surface and the diffusivity coefficient. find eclosed the program.

best regards!!

Hello,

Your program seems to be a structured finite difference code. I do not see how you want that to interact with Code_Saturne (or do you simply want do do something similar with more complex geometries using Code_Saturne) ?

I recommend simply experimenting with a simple species representing the concentration, which you may inject using some boundary condition of your choice. You can then improve that using source terms instead or in addition to boundary conditions (in case the formaldehyde is produced by a porous media inside the domain) or more complex, Fortran-defined (cs_user_boundary_conditions.f90) boundary conditions (for example if the rate of injection of formaldehydes depends on some surface or near-surface temperature, or some other law you provide).

You may also use a user law for density to account for the density of a mix with a given formaldehyde fraction, but I would do that as a last step.

Regards,

Yvan