I obtain an outflow of scalars at the inlet where these scalars aren't defined at all. What is the problem and how to solve it?

P.S. I think that all the troubles (there is a recirculation also) are because of the pressure boundary, but I can't not to use it.

Thanks, Julie

Hi Julie: If this happens in the first few iterations, you can ignore it. If this still happens after a few hundred iterations, You can 1. turn the mean option on in the pressure BC. This will eliminate the pressure difference on the pressure BC plane. 2. check the location and value of the refrenece pressure. 3. move the location of the pressure boundary upstream. sometimes, it makes sense recirculation exists if you have a very strong adverse pressure gradient.

If you could post your problem in more detail, that will be very helpful to figure out the problem.

regards, ccy