If I split the fluid domain in to seperate regions in-order to control and refine meshing, what boundary condition do i need to apply to make the seperate regions as one continum???

Thanks all

Russ

In Gambit, do not define any boundary condition at the border of the two domains if it is one continum. Have a try. You will find if you do not define any boundary there, that "border" will not show in your boundary conditions in Fluent. If you need a line/face for refining mesh in Fluent, I think a better way of doing it is to define a line/face in Fluent. I have done that.