Ideal Crusing Altitudes for the Jet Engines

[Volt]

Does anyone have accurate figures for the ideal altitude for both engines? Sorry if this has been posted somewhere else; I have been trawling but fifteen minutes of thread-scanning has yielded only 15km for the Turbojet.

It would be nice to have these figures in the most visible places possible.

[vexx32]

Whilst I don\'t have *accurate* figures, I know that the air starts to become thinner around 5,000m, and the performance of the standard jet engine peters out shortly above this.

The air becomes too thin for the turbojet engine (the one that isn\'t supposed to work in lower-atmosphere, but does; the one with fins all over the back of it) around 15,000m or so.

Keep in mind that the engines don\'t ever 'cut out' at any altitude; they slowly stop working as the air thins out. So, you can get almost to 20,000m with the turbojets if you have enough of them and a light enough plane.

At the moment, I think the aerospike still functions as a rocket engine; not sure if this is intended or C7 hadn\'t quite gotten around to changing it.

[Temstar]

Aerospike IS a rocket engine, even in real life. Aerospike rockets have the exact same machinery as normal rocket engine (fuel and oxidizer turbopump, combustion chamber, regeneratively cooling, etc), it just has an unusual nozzle that\'s more efficient at a wider range of altitudes.

[vexx32]

Ah, thanks for clearing that up

[Elven_sword]

Ramjets start becoming a problem for me at 20km.

[LukeTim]

Ramjets start becoming a problem for me at 20km.

There are ramjets? Is there a second page of engines that I haven\'t noticed yet?

I saw the ramjet intake, which I thought was odd since I thought there\'s no ramjet engine...

[sal_vager]

The ramjet intake is meant for the high altitude engine I think, but airflow didn\'t make it into 0.15

[LukeTim]

The ramjet intake is meant for the high altitude engine I think, but airflow didn\'t make it into 0.15

Which is the high altitude engine? I only see the standard Jet and the Turbo Jet.

[sal_vager]

The turbojet was meant to be, but C7 only had time to set airflow to true globally, the turbojet isn\'t supposed to work at low altitudes.

[LukeTim]

At the risk of sounding either like an idiot or a knobheaded pedant, I was under the impression that a turbojet isn\'t an engine that only works at high altitude... and that it works in a very different way to a ramjet so would use a different kind of intake.

[sal_vager]

I know what you mean, but only some engines could be made stock or it\'d get overloaded with parts, and squad decided on the turbojet for the high altitude engine, ramjets would be a lot better.

The Kerbal turbojet isn\'t meant to work very well below about 6km, but nothings balanced yet so even that altitude may change.

[Temstar]

The turbojet says something about ramjet intake. Maybe in the future it will work like this:

turbojet + circular intake = normal turbojet, works for say <15,000m

turbojet + ram air intake = more powerful ramjet, works <25,000m, has reduced efficiency at high air density and/or low air speed

basic jet + circular intake = normal jet

basic jet + ram air intake = explosion

[LukeTim]

The turbojet says something about ramjet intake. Maybe in the future it will work like this:

turbojet + circular intake = normal turbojet, works for say <15,000m

turbojet + ram air intake = more powerful ramjet, works <25,000m, has reduced efficiency at high air density and/or low air speed

basic jet + circular intake = normal jet

basic jet + ram air intake = explosion

That\'s cool, I guess.

Love to see a scramjet mod sometime.