2D space for planar and axisymmetric computation domain
recently, I've been confused about an example in a fluent tutorial. the above picture shows the real geometry of the computation domain. in specific, it's a cylindrical pipe with porous filtering media inside.
the computation domain is two-dimensional. after imported into fluent, it is selected to be planer in 2D space panel instead of axisymmetric in the tutorial. I am wondering does planar mean infinitely big plane? as far as I am concerned, cylindrical pipe is definitely not infinitely big planes. or am I misunderstanding the meaning of planar?
can anybody help me to understand it ?
thanks very much