I’m clear on the “dump raw fuel into the exhaust” thing, but… I always thought a flame could not be supported in a supersonic airstream. (I’ve read that the air is slowed down to subsonic velocity by the shape of air intakes in jets)
I’m asking this question because of something I believe to be a myth. A soldier told me he put a roll of toilet paper that had been soaked in a flammable liquid over the end of a tank main gun round. It left a trail of flames all the way downrange. I had heard this before when I was on active duty (I’m National Guard now). I never said anything before, but I told this guy there’s no way in hell, an told him why this can’t be possible. “But what about afterburners?” he said. Damn!
I think you’re confusing the problems in getting scramjet (supersonic combustion ramjets) to work with the conditions needed for plain old fire. The trick seems to be getting the shock waves to work for the engine rather than against it.
The air going though a turbojet or turbofan engine is not supersonic thought the aircraft may be. Shock waves do unpleasant things to spinning fans and compressors so great pains are taken to keep the flow through the engine subsonic. In some planes the intakes are designed to do this passively but in others there are active intake restrictors to accomplish the same purpose. The F-14 for example has compute controlled movable ramps in the upper part of the intake. Making sure those ramps work is one of the most critical pre-flight checks for an F-14.
Argh! I should read the OP more carfully before posting.
As for the flaming artillery I really wonder if the TP roll was still on the nose of the round in flight. I suspect the round tore through the center and went on its merry way while the flaming debris followed. I think that if the roll stuck to the nose it would have thrown the round off its normal trajectory.
FWIW I use a sort of “tracer” in the black powder ammunition I compete with. Under each bullet is a beeswax cookie of lubricant. Black powder burns much hotter than modern smokeless propellant so the wax is melted and burning by the time it leaves the barrel. It makes a nice little smoking trace of the bullets path for the most part but often the cookie separates and takes an erratic path. This ammunition isa just supersonic in rifles and that doesn’t keep the wax from continuing to burn.