Do Jets Work On Eve

[Tremzack]

Title says it all just a simple question as i have not been to eve yet

[NovaSilisko]

No. The only bodies they work on are Kerbin and Laythe. On other atmospheric bodies, they will use up fuel but not produce any thrust.

[Tremzack]

Bummer, back to the design board

[Temstar]

What if we use a 3 stage pure rocket powered spaceplane for Eve lander? It will deorbit and glide to a "water" landing in the mercury ocean. The Kerbonauts can get out and do some SCIENCE on top of the wings then get back in. The the lander will take off on a small number of aerospike rockets (TWR less than 1 when taking the weight of the whole craft) and fly in depressed trajectory using lift from the wings just like a Kerbin plane. Climb to say 30,000m, stage and blow off stage 1 and become a smaller spaceplane with the canard of the previous stage as the main wing of this stage, climb higher and stage again and then accelerate to orbit on pure rocket powered stage 3?

[MaverickSawyer]

Hmm. Sounds reasonable... but what about the Damned Aerospace propellors? Those might be the ticket on Eve. Just watch the torque reaction!

[Qumefox]

He's likely trying to do it with stock parts. Like me.

[Temstar]

The wiki says

Jet engines function in Eve's atmosphere, but do not provide useful thrust near the surface due to the density of the air.

Which sounds to me like as if the person wrote that DID manage to see useful thrust from engines at higher altitude. Can anyone confirm if that's true or not?

[NovaSilisko]

No, it's not true. It's a false observation - the jets will sound like they're running and will use up fuel, but no thrust is produced.

[MaverickSawyer]

Non-combustion friendly atmosphere on Eve?

[TheHengeProphet]

It looks like it would be an iodine-based atmosphere; however, no matter what the wiki says, I'll take Nova's word for it (him being a dev and all). I do want to test it, just for spits and squiggles, though (goes with me on the path of stranding pilots on every body but Jool and the sun).

[Qumefox]

It looks like it would be an iodine-based atmosphere; however, no matter what the wiki says, I'll take Nova's word for it (him being a dev and all). I do want to test it, just for spits and squiggles, though (goes with me on the path of stranding pilots on every body but Jool and the sun).

I actually have a ship with jet engines eve bound as we speak

If the game would quit locking up on me anyway...

[Tommygun]

So does this mean that the helicopter engine won't work on Eve ether?

I was working on a Roton rocket for Eve.

[Qumefox]

By the way, the atmo may start at 97500 on eve, but aerobraking doesn't start to work until you get below 90k.

slow process.. almost out of (non-jet)fuel. trying to save what I have left to get a day side deorbit.

[Qumefox]

Aaaaannd.. Nova is correct. (not that I doubted him, was a good excuse to strand more kerbals on Eve ) Jet engines in fact, do absolutely nothing at any altitude on Eve.

Experiment completed.. I'm going to bed.

[Grand Lander]

Ahh going to say you should try before you ask!

[henryrasia]

on other atmospheric bodies, they will use up fuel but not produce any thrust.

nova, y u make us suffer???!!!

[OceanFire]

This does make since that jets only work on Kirbin and Laythe because there the only bodies that seam to contain oxygen or something like it. While Eve seams to be made up of methane, or something of the like.

[RoboRay]

An oxygen environment isn't strictly required for combustion... hydrazine burns nicely in CO2, for example. Alternative fuel tanks for non-O2 combustion engines?

[Qumefox]

I have to question KSP's jet engine modelling now though after playing with it more. I know this is a game, it seems they're still trying to (eventually) achieve parts that basically work and perform roughly like their real life counter parts.

How they seem to work in KSP currently:

Fixed fuel flow (full throttle at sea level uses the same amount of fuel as running one in space)

Efficiency decreases with altitude.

thrust decreases with altitude.

How jet engines behave in reality:

Fuel consumption decreases with altitude.

efficiency increases with altitude, until it hits optimal, then starts decreasing again as the air gets too thin.

thrust remains relatively static from sea level to optimal altitude, then falls off as altitude increases past optimal.

I'm not sure how hard it would be to make them behave properly in game.. but at minimum I think the fuel usage on current parts should be changed so that the less thrust they make, the less fuel they use. and when they get to 0 thrust, they use 0 fuel. (since well.. if there's no oxygen to support combustion, your not going to be using any fuel either...)

[NovaSilisko]

They function like that on Kerbin and Laythe... On other bodies, you're just pumping fuel into the engine and having it wasted.

Also, it's not altitude that matters, it's air density, which jets in KSP base their calculations off of.

[Xellith]

My eve landing plan:

Study the topography.

Land a rover near the tallest parts of the planet.

Land next to rover.

This way when attempting an exit of the planet there would be less atmosphere required to pass through and thus increase the chances of a successful launch. The same method applies with the Rock closest to the sun

Still.. waiting for the new MMI pack thingie with working solarpanels and whatnot.

[Qumefox]

They function like that on Kerbin and Laythe... On other bodies, you're just pumping fuel into the engine and having it wasted.

Also, it's not altitude that matters, it's air density, which jets in KSP base their calculations off of.

That doesn't write off what I posted, which was that a jet engine outside it's environmental operating range (in space, in a different atmosphere) shouldn't continue to burn fuel at the same rate as if the same engine at sea level in an oxygen enviornment...

We don't have to micromanage the oxidizer/propellent ratios manually for maximum thrust for chemical rockets in game.. They run as efficiently as they can all the time. I'm just asking for jet engines to be the same way.

And bringing up air density is just arguing semantics. It's what I was meaning with altitude, since it's primarily what you get with increasing altitude, along with drops in temperatures.

My point though.. is that actual jet engines have subsystems that maintain proper fuel/air ratios for proper combustion.. just like chemical rockets have subsystems that maintain proper oxidizer/propellant ratios..

When a jet engine lacks enough oxygen to run, it'll flame out, and cease using fuel entirely (won't make noise either ).

Right now we just get a throttle attached to a fuel valve pretty much and engine management be damned.

I think the 'air density' behavior should be fixed too, since the thinner the air, the better jet engines work... to a point.

[TheHengeProphet]

*snip*

Right now we just get a throttle attached to a fuel valve pretty much and engine management be damned.

*snip*

I like to think of it this way: Kermen are rocket scientists, not aerospace engineers. So far as they know, fuel management is all there is to jet engines. More fuel? More power!

To my knowledge (though I may be horribly mistaken and blowing hot air), early jets worked fairly similarly.

[Qumefox]

I like to think of it this way: Kermen are rocket scientists, not aerospace engineers. So far as they know, fuel management is all there is to jet engines. More fuel? More power!

To my knowledge (though I may be horribly mistaken and blowing hot air), early jets worked fairly similarly.

They did, however, even the early ones worked more efficiently in 'less dense' (high altitude ) cooler air.

I guess I can sum up the issues I have with the current jet engines as modeled in KSP with this statement.

If you want maximum fuel efficiency, you fly low and slow..(I just tested it) which is pretty much the opposite of how you get the most out of jet engines in real life.

Actually the normal jet engine does gain some efficiency with altitude (seemed to peak at 3km or so).. it still wants to go slooow though or it drops off.

The turbojet however wants to stay on the ground and go 60m/s to maintain peak efficiency.

Edited October 10, 2012 by Qumefox

[cardgame]

My eve landing plan:

Study the topography.

Land a rover near the tallest parts of the planet.

Land next to rover.

This way when attempting an exit of the planet there would be less atmosphere required to pass through and thus increase the chances of a successful launch. The same method applies with the Rock closest to the sun

Still.. waiting for the new MMI pack thingie with working solarpanels and whatnot.

Not a bad plan at all, but watch out for broken collision meshes.

Also, the current MMI Pack does have working solar panels. You just need to install all the requisite plugins.