Doubleing up on fans?

Ok so this might sound stupid but here it goes:

So i you take two pc fans and put them in an inline set up. Will it double the CFMs? Will it increase them at all? How close would you be able to put them and still have an effect?

Thanks a lot

CG

Fans must be ran in parallel to double CFM (assuming same cfm fans and equal ducting parameters)

A length of duct of whatever shape and size and run, twists and turns etc, can only move a max amount of air per period. Same with the fans. Fan of equal spec can not make the other fan output greater than it's input.