What does "4 x 4" actually mean?

Nope, jets are internal combustion, the combustion take place at, or generates, high pressure. Confusingly, a steam turbine engine is external combustion. The combustion takes place at atmospheric pressure, heats the water, creating the steam at high pressure that does the work.

I disagree. I’ve already explained the difference. We’ll leave it at that.

Not according to wiki or every other source I can find. This is listed under internal combustion:

“With gas turbine cycles (notably Jet engines), rather than use the same piston to compress and then expand the gases, instead separate compressors and gas turbines are employed; giving continuous power. Essentially, the intake gas (air normally) is compressed, and then combusted with a fuel, which greatly raises the temperature and volume. The larger volume of hot gas from the combustion chamber is then fed through the gas turbine which is then easily able to power the compressor.”

I would argue a burner can is “inside” a turbine engine. I guess the other way of approaching it is to treat it like the “hole in the donut”: not part of the donut. I know the GI system is often considered " external " to the body for this reason.


In systems class, it was explained to me that a turbine is a four-cycle engine, just with all four cycles occurring constantly in dedicated sections of the engine: the air intake is “intake”; the compressor stages are " compression"; the burner can and power turbines are “power”; and exhaust is self-explanatory.

Per Wikipedia:

A second class of internal combustion engines use continuous combustion: gas turbines, jet engines and most rocket engines, each of which are internal combustion engines on the same principle as previously described.

Remembering an aircraft flying in over the runway at 450 mph, pulling a 180, putting on full afterburners and landing on the runway, also f15s taking off putting full afterburners on and disapearring into the sky