It is theoretically possible, through the use of proper geometric calculations and coaxial bevel gears/axles, to make a large OD fan on a robot that is very wide and very short (length-wise) -- something on the order of 8" long x 48" wide -- in order to create a massive amount of turbulence in front of any disc trajectory (and do a 'fly-by' of the refs
). Of course, one would want to use wheelie bars to prevent tipping while driving.
The practical use of such a robot is up for conjecture though -- there wouldn't be much room to add manipulators that get a positive point differential for that robot if it were solo.