Show and Tell - NERV-US

[StarSlay3r]

Behold, the completed Nuclear Engine for Rocket Vehicles - UpScaled, or NERV-US (thanks for the name suggestions)! This engine's nozzle retracts when the LH2 engine switches to its O2-injecting afterburner mode. Model by Jonathan Cooper.

[AtomicTech]

HECK YEAH!!!!!!!!!!!

Edited October 1, 2021 by AtomicTech

[Panical]

Nervous nuclear engine

[kAerospace]

LETS GOOOOOO!

[AtomicTech]

If just one engine looks this beautiful, I wonder how all the others are going to.

Spoiler

To be honest, I think I'm going to cry happy tears when I'm in KSP 2's VAB.

 

[LezRowl]

A lotta cool things to understand. What exactly are the differences between O2 and regular mode?

[mattssheep4]

I'm sad that enigine effects aren't included, but aside from that....

[StarSlay3r]

5 minutes ago, LezRowl said:

A lotta cool things to understand. What exactly are the differences between O2 and regular mode?

 

The engine has 2 modes:
Low-thrust, high-ISP mode that uses liquid hydrogen in the same way that the NERV does.
High-thrust, low-ISP mode that burns both liquid hydrogen and oxidizer (think of this as an afterburner that dumps LOX into the nozzle itself for extra kick)

In low-thrust mode, a large vacuum-rated nozzle telescopes downward, extending the overall nozzle length. In high-thrust mode, the nozzle is short.

[Inglonias]

Wouldn't it be advantageous to let us run the afterburner with the nozzle in vacuum mode as well to increase efficiency when firing high-thrust in a vacuum (IE something like Tylo)? Something like an in-beween?

[TheOrbitalMechanic]

13 minutes ago, Inglonias said:

Wouldn't it be advantageous to let us run the afterburner with the nozzle in vacuum mode as well to increase efficiency when firing high-thrust in a vacuum (IE something like Tylo)? Something like an in-beween?

I think you can still run either mode anywhere; high-thrust mode is just more tailored to atmospheric flight, so the nozzle shortens.

[Yellowburn10]

19 minutes ago, KSPStar said:

 

The engine has 2 modes:
Low-thrust, high-ISP mode that uses liquid hydrogen in the same way that the NERV does.
High-thrust, low-ISP mode that burns both liquid hydrogen and oxidizer (think of this as an afterburner that dumps LOX into the nozzle itself for extra kick)

In low-thrust mode, a large vacuum-rated nozzle telescopes downward, extending the overall nozzle length. In high-thrust mode, the nozzle is short.

Man, this means we could potentially have SSTOs needing only one engine for all of it's tasks. I'm just all the more excited to get to try this stuff out!

[Nirgal]

Noice!

[Inglonias]

5 minutes ago, TheOrbitalMechanic said:

I think you can still run either mode anywhere; high-thrust mode is just more tailored to atmospheric flight, so the nozzle shortens.

I know. What I meant was that all other things being equal, a larger nozzle gets you a higher exhaust velocity, which gets you a higher ISP. So the afterburner mode would (in real life, anyway) be more efficient in vacuum if the nozzle were extended than if it were not. That said, it is a game. They can make the part's stats whatever they want.

Edited October 1, 2021 by Inglonias

[JadeOfMaar]

25 minutes ago, LezRowl said:

A lotta cool things to understand. What exactly are the differences between O2 and regular mode?

If you're a mod user, I happily point you to Nertea's Kerbal Atomics package. If not, well:

The use of Oxidizer (or LqdOxygen, whatever KSP2 devs go with) declares that this engine is LANTR (Lox-Augmented) or BNTR (Bimodal). Regular mode is when Hydrogen alone is the propellant and the Isp is highest. When you add LOX, the Isp drops a lot but is still above the chemical rocket range and the thrust is much better in vacuum and is very good at sea level. (The Kerbal Atomics engines have the vacuum Isp range of 500s to 530s. This is far above 345s where the best of stock engines reach.)

17 minutes ago, Inglonias said:

Wouldn't it be advantageous to let us run the afterburner with the nozzle in vacuum mode as well to increase efficiency when firing high-thrust in a vacuum (IE something like Tylo)? Something like an in-beween?

I guess the devs don't care to provide for that. imo they've done plenty to create an atomic engine that'll satisfy everyone who simply wants an atomic rocket for SSTOs that operate in atmosphere. Perhaps there will be a companion engine that's only good for vacuum. There you'll have what you 're describing.

[SheepyKSP]

This looks extremely epic, I am quite excited for KSP2!

[shdwlrd]

I was wondering how the nozzle moved up and down, then it hit me, screw drive. Duh... Nope, proven wrong by Mr. Simpson.

Nice work as usual. Glad to see an actually useful NERV being added.

Edited October 2, 2021 by shdwlrd

[TheOrbitalMechanic]

27 minutes ago, Inglonias said:

I know. What I meant was that all other things being equal, a larger nozzle gets you a higher exhaust velocity, which gets you a higher ISP. So the afterburner mode would (in real life, anyway) be more efficient in vacuum if the nozzle were extended than if it were not. That said, it is a game. They can make the part's stats whatever they want.

Ah yeah, I understand now. In that case, maybe nozzle functionality is separate from fuel usage or something, but at the end of the day, yeah, it's a game.

[RealKerbal3x]

WOAH that's one mean looking engine!

[gussi111]

It's amazing how detailed everything will be in KSP 2!

[Deddly]

It's Beautiful! But I'm having difficulty seeing where the extending pistons retract into. They seem to just magically extend and retract, no? 

Probably not important. 

[mcwaffles2003]

8 minutes ago, Deddly said:

It's Beautiful! But I'm having difficulty seeing where the extending pistons retract into. They seem to just magically extend and retract, no? 

Probably not important. 

They don't retract, they're stationary. The nozzle extension seems to be on rollers. You can see the rods inside the vacuum nozzle when it is retracted.

[Deddly]

7 minutes ago, mcwaffles2003 said:

They don't retract, they're stationary. The nozzle extension seems to be on rollers. You can see the rods inside the vacuum nozzle when it is retracted.

Ah I see those rods extending through to the inside now, thanks! I'm still unsure what is it that moves it back and forth, though. 

[shdwlrd]

7 hours ago, Deddly said:

Ah I see those rods extending through to the inside now, thanks! I'm still unsure what is it that moves it back and forth, though. 

Screw drive. One or more rods rotate to raise or lower the bell. (Similar to how some automatic lift hatches work in cars.) Nope, corrected by Mr. Simpson.

Edited October 2, 2021 by shdwlrd
Nate stated the correct operation of part.

[Pthigrivi]

Looks amazing yall  

Question for folks who know more about real engines: can this bit get scrunched up a bit for nutters like me who will try to use this for big landers? I feel like it's nice to have that vertical dimension as condensed as possible in that application.

Edited October 1, 2021 by Pthigrivi

[AtomicTech]

3 minutes ago, Pthigrivi said:

Looks amazing yall  

Question for folks who know more about real engines: can this bit get scrunched up a bit for nutters like me who will try to use this for big landers? I feel like it's nice to have that vertical dimension as condensed as possible be in that application.

Maybe a "scrunched" variant named NER-EZEE.

Spoiler

NER from NERVA/NERV, EEZE from Squeeze.