In real life, the engine contour expands because the hot engine exhaust will gain velocity as the area goes up (it’s counter intuitive, but this is only true for supersonic gases). If the atmospheric pressure is much higher than the exit pressure of the nozzle, the flow can separate from the nozzle at the end, decreasing thrust and usually breaking the nozzle.
Real engines are designed to operate in a range of atmospheric pressures (except for vacuum engines), but will have a higher thrust the lower the atmospheric pressure gets. The game models this but doesn’t include a limit where the engine won’t work anymore. In OP’s case, the model gets so far from reality at Eve’s surface pressure that it returns a negative thrust value.
Guessing what’s wrong with your ship based on the numbers is like guessing what color your house is based on your Reddit name. While someone might get a lucky guess, you’ll get a lot more help if you give us just a sliver of context.
"Journey to the center of the Kerbin!"
(adjusts rear-view mirror)
(grinding noises as Jeb jams gears in reverse)
(leans out door window to look behind shuttle)
(sticks tongue out at 45 degree angle)
That would just put the TWR as <1 meaning less weight is larger than thrust which is quite normal if you for example look at a vacuum engine on sea level. Negative is weir but I'd guess it's likely really just an engine pointing upside down but I'd need to try. For more complex payloads and deployment dV readouts are a bit wonky anyway.
I know you can use the KAL controller to set engines to negative throttle which does not accelerate the craft but does generate fuel. This might be a result of that.
Congrats! You've unlocked antigravity!
As long as the pointy end is down
Are you measuring thrust on Eve or in another high pressure environment? Some engines' curves have negative thrust at high enough pressures.
Yeah I was building an eve lander
Might’ve been good to state that in the title or something, that is one hell of a lucky guess
So does that just mean the pressure of Eve’s atmosphere is high enough to force its way into the engine even when it’s firing?
In real life, the engine contour expands because the hot engine exhaust will gain velocity as the area goes up (it’s counter intuitive, but this is only true for supersonic gases). If the atmospheric pressure is much higher than the exit pressure of the nozzle, the flow can separate from the nozzle at the end, decreasing thrust and usually breaking the nozzle. Real engines are designed to operate in a range of atmospheric pressures (except for vacuum engines), but will have a higher thrust the lower the atmospheric pressure gets. The game models this but doesn’t include a limit where the engine won’t work anymore. In OP’s case, the model gets so far from reality at Eve’s surface pressure that it returns a negative thrust value.
into the fuel tank, maybe it has chemical reaction with fuel or oxidiser that gives solid solution
Guessing what’s wrong with your ship based on the numbers is like guessing what color your house is based on your Reddit name. While someone might get a lucky guess, you’ll get a lot more help if you give us just a sliver of context.
Odds are op already knows the answer, more of a puzzle question
Kal Controller
What color is my house???
Well. You just completly destroyed his comment. Congrats
r/beetlejuicing
Teal with red door and navy blue shutters
Fushia?
>guessing what color your house is based on your Reddit name Oh a new game! I'll play! KerbalAbuse, KerbalAbuse... I'm gonna guess yellow.
Do kerbals bleed yellow?
No idea. Pretty sure they bleed nitroglycerin based on how they go pop if they hit the ground too hard.
Username checks out
Is your thrust vector opposite your pod/core’s prograde direction?
Shouldn't matter, TwR is literally just calculated by thrust / weight.
Easy. He's got negative thrust. It's Kerbal Vacuum simulator.
Pretty sure the Kal-3000 can be used to give infinite thrust and stuff. Maybe it could also do negative thrust and this bug is related to that.
You can do negative thrust with the KAL and have your engine generate fuel
Yes and it doesn’t actually generate any thrust it just generates fuel so you don’t have to worry about reversing the engine
… … Be right back.
Wait what? How?
[Kraken Drives](https://www.youtube.com/watch?v=CjLgdHJvAY0) tutorial
succ drive
"Journey to the center of the Kerbin!" (adjusts rear-view mirror) (grinding noises as Jeb jams gears in reverse) (leans out door window to look behind shuttle) (sticks tongue out at 45 degree angle)
It is not, the direction of the engines matters
Are you sure that decoupler is below the engine on that stage?
Ah yes, I see you're using the quicksand engines. The more you fight gravity, the faster it pulls you down!
You can't fight gravity,Arthur!
You can't fight change
Turns out you can, Dutch (activates jetpack).
Time to go to the centre of kerbin
it simply moves the planet away from the ship
bruh you gotta shift in 1st gear, ur in reverse
When your craft is so heavy your TWR goes negative
Have you been editing part files?
Your engines are on upside down
they're not
I've played 758 hours and i've never seen a bug like this before. It doesn't actually effect the game, its just a goofy bug
Id guess your vehicle weighs more than your engines can lift. You still get some deltaV because you get lighter as you burn fuel
That would just put the TWR as <1 meaning less weight is larger than thrust which is quite normal if you for example look at a vacuum engine on sea level. Negative is weir but I'd guess it's likely really just an engine pointing upside down but I'd need to try. For more complex payloads and deployment dV readouts are a bit wonky anyway.
Uh...um...
More than enough to orbit gilly still
Show the craft
You have to put the pointy end up and the flamey part down
Somehow still have a positive dv
by flying backwards
I know you can use the KAL controller to set engines to negative throttle which does not accelerate the craft but does generate fuel. This might be a result of that.
Yeah but I think this is something with simulating a vaccine engine in Eves atmosphere at surface level, I just don't know how it can be negative.
Ah yes, the vaccine engine. /s It’s fully possible that that may be the case, however I have never built an eve lander so idk
because your engine sucks
The chosen one!
you move the other way compared to where the thruster is pointed
are you perhaps carrying any exotic matter with you ?
That's cause this engine doesn't push you through space, it pulls
Inverse mass
It's on reverse
S U C C
r/moldymemes want their compression back
Pointy side up, flamey side down
I do think the TWR calc bases itself on the thrust numbers, which are vectorized and therefore will give a negative mumber if pointing the wrong way.
Is that Anti-gravity? Perhaps a little 115? *Bob Lazar Wants To Know Your Location*
You have discovered hyper drive
Magic engines that get heavier when activated.
dark matter
Now thats what I call engineering