Hi

What is convective boundary condition and how can i impose it? I am working on CFX 11. I am simulating a flow over an airfoil which must use covective boundary condition at the outlet. Thanks

Mani

If I am not wrong, convective BC is the same as the Neumann BC... look for it in google... good luck...

I have no idea what Neumann BC is but i think know now what convective BC is! Its more like an outlet BC. It is used to prevent any sound reflection back in domain. Thanks for reply.

Regards Usman

In general the convective BC declares that heat flux normal to the boundary is given by this equation:

q_n = alpha (T_inf - T)

q_n: heat flux normal to the boundary; alpha: heat transfer coefficient (maybe give, or you get it from Nusselt-Equations, or maybe it your task to calculate it ...); T_inf: Temperature of the farfield; T: Temperature at the boudary

You wrote something about an outlet BC. An outlet BC must be a given velocity normal to the boundary. Like this:

u*n_x+v*n_y = constant

u: x-velocity; n_x: component of normal-vector in x-direction

Correct me if I'm wrong.

P.S. How can I do linebreak in this forum?

Why do you need to do line break in this forum. Are you working with LES sega.

Mani

What's LES?

Large Eddy Simulation is a superior technique to traditional RANS modelling. RANS modelling is crap, if you are still using it, give it up. LES is taking over!

Mani