we all know the fact but why are they that inefficient if they just burn some more fuel? today i just realised how to fix this in real life, let me explain. when an afterburner is on, it burns fuel in order to heat air and force his exit through the nozzle as heat expands it, we can see this just by looking at the exhaust plume. and here is the problem, if we are able to see the plume from the side of the engine, that means fuel is still being burned when it exits the engine, nd so it is heating air that is not forced to push the aircraft, decreasing fuel efficiency, if we could install a sufficiently long nozzle that the complete plume was hidden, air would be expanded even further and will generate more thrust, if we just lower the fuel amount used we could achieve better afterburner efficiency at the cost of a longer nozzle capable of resisting overexpansion of the hot ait and the subsequent exhaust heat
if anyone that reads this for any reason owns a jet engine of any kind could you please try if this would work? we could get the collier trophy for this discovery if it proves tue