bigger or smaller enclosure box
 

hi,
im doing analysis on a blunt body.
which one is better, using bigger or smaller enclosure box? and why?

any opinion?

cheers

If you want to model the body moving through the open atmosphere then a big enclosure box (because it reduces proximity effects). If you want to model the body in an enclosed space like a wind tunnel then model the wind tunnel as the enclosure.

do size of enclosure box will affected the results?
why is that?

Yes it does. It is one of the basic checks you need to do for far-field simulations. When your boundaries are too close it will cause an error in the simulation by artificially constraining the flow.