Jet Plume Expasion

[HighFructose]

I was playing realism overhaul, and using AJE. I used the engine that is like the engine that looks like the whiplash. As I flew up to 10,000 or so meters, the jet plume was expanding. I believe it is using the aerospike plume, but it got me wondering: do jet exhaust plumes expand like rocket plumes?

I would think yes, because the ambient pressure at that altitude would be fairly low, and the exhaust would expand. 

[p1t1o]

Just look up at the contrail an airliner leaves, its often as wide or wider than the wingspan - they expand a fair bit, yeah.

[NSEP]

Yes, why would they not?

[Steel]

Yes, absolutely.

[mikegarrison]

10 hours ago, p1t1o said:

Just look up at the contrail an airliner leaves, its often as wide or wider than the wingspan - they expand a fair bit, yeah.

That's not necessarily meaningful. Contrails can and often do get rolled up into the wingtip vortices.

As for answering the question, for a turbojet it would be similar to a rocket. But for a turbofan there are actually two exhaust jets, one for the core and an annular one for the fan. The core jet expansion is heavily influenced by the fact that it runs into the fan jet.

Edited September 2, 2017 by mikegarrison