by CAFedm » Mon Jun 28, 2010 10:20 pm
The only other item to consider is that high Mach aircraft tend to have some sort of boundary layer splitter, or suction device (like the plate found in front of the intake of an F-18A/C). This helps direct airflow into the engine while slowing it down to subsonic speed, so that the engine doesn't surge. Moving shock cones, like on the SR-71, likewise have the same effect. Aircraft with square inlets (F-14, F-15) have interior moving ramps in their intakes. So, anything goes, as long as there's some means to slow the air entering the engine.
Brian