hi,

i want to know about out flow conditions.

in particular i want to know about zero gradient condition and also convective outflow condition.

can both of these cause reflections back into the domain, in both low and high speed flow.

is the implemtation of these conditions different in low and high speed flow?

i also read that there are sometimes problem at the outflow in an eliptic problem...what exactly does that mean?

thank you.

Hi !! Check out the following reference:

Hasan, N., Anwar, S.F. and Sanghi, S. "On the outflow boundary condition for external incompressible flows: a new approach", Journal of Computational Physics, 206, pp. 661-683, 2005.

Regards, ramp