[doneatlast]

2D or 3D?
Please need some enlightenment as a newbie in CFD. On what condition or conditions can I use 2D or 3D as domain geometry? I mean what kind of problem set will prompt me to go for 2D or 3D and how will my decision affect my overall report

[som87]

For flow "situations" where there is no disturbance along a co-ordinate, you can use 2D cases.For example say a flow over circular cylinder, placed perpendicularly to the flow with constant dia.

Thus you neglect the flow disturbance along its axial plane.

basically any case where you can neglect any of the X, Y, Z momentum equation as well as the velocity gradient for a particular direction