[WIP] Nert's Dev Thread - Current: such nuke, wow

[NHunter]

While I'm all for having less parts when it comes to fuel tanks, I still find it a bit annoying that FissionParticles inline tanks are size2 only when the only engine using them is size3. Yes, there are also surface-attachable versions of those thanks, but still...

[Nertea]

17 hours ago, RedParadize said:

@NerteaI agree with you on having architecture for specific purpose. Its not that I would wish for a one size fit all, its more about that there is no engine that cover modest size lander atm. Say you want to land on Laythe, atm the only engine that is good for that is the JR20A, that one is much more powerful and heavy than needed, so a rocket much bigger than the actual need will have to be carried to Jool orbit to do so. Maybe that type of engine can't be scaled down any further, I wonder if there would be one type that could trough.

About radiation, most of fusion engines produce less radiation than fission ones. Off, they do not pose as much hazard when close to them, wherever we are talking about direct radiation or contamination. When compared to space level of radiation it isn't that much of a concern, crew needs some level of protection either way. As for when the engine run... well you need a shadow shield that's for sure.
 

 The main reason these conceptual engines are big is because when you have a high power flux in a small space, it is very difficult to keep it from melting. You have two options - add more propellant to carry the heat away, which reduces performance, or make the engine reaction chamber / nozzle bigger so there is a lower power density. With nuclear engines, this gets worse, because the radiation flux is intercepted by the engine components, heating them up. This is also one of the reasons the engines are very skeletal, this ensures lower radiation interception.

So if you want to scale down an engine, you have a very large engineering challenge, which you will solve usually by increasing propellant vs fuel flow (lowering ISP), lowering overall jet power (lowering total performance), or massively increasing heating demands. 

The J20A is an engine where I did that - take the Discovery engine, scale the reactor down while maintaining the power, increase the propellant flow a lot. This gets you smaller without tons of heating, but you see the performance doesn't work quite as nicely at that scale. It's not a ton better than chemical engines.

Small essay, but I hope you get my reasoning here. I don't claim realism in my mods, but one of the major engineering challenges of far future engines is scale and I want to represent that.

4 hours ago, Plutron said:

Why not use a chemical/nuclear thermal engine for the lander, and use a fusion engine for the tug/main vessel? 

That's usually the architecture I have in mind.

2 hours ago, NHunter said:

While I'm all for having less parts when it comes to fuel tanks, I still find it a bit annoying that FissionParticles inline tanks are size2 only when the only engine using them is size3. Yes, there are also surface-attachable versions of those thanks, but still...

Sure but do you really want my limited time used on that? To some extent that is why those models have all the compact variants.

Edited November 14, 2020 by Nertea

[NHunter]

No, I do not -- which is why I'm not saying there should be 3.75 tanks for FiP.

I just love my stacks neat and without varying part diameter... Which, I guess, you can maintain with fairings or hollow parts (with 2.5m tanks hidden inside them). So it's not a big deal.

[WarriorSabe]

6 hours ago, Nertea said:

Sure but do you really want my limited time used on that? To some extent that is why those models have all the compact variants.

What if you add a B9 switch for scale, that literally just makes it bigger or smaller, reusing the same models you already made?

[CDSlice]

32 minutes ago, NHunter said:

No, I do not -- which is why I'm not saying there should be 3.75 tanks for FiP.

I just love my stacks neat and without varying part diameter... Which, I guess, you can maintain with fairings or hollow parts (with 2.5m tanks hidden inside them). So it's not a big deal.

Alternatively if you get Near Future Construction you can get some 3.75m skeletal trusses that you can stick the 2.5m tanks inside. It'll probably look cooler that way as well.

[Nertea]

2 hours ago, WarriorSabe said:

What if you add a B9 switch for scale, that literally just makes it bigger or smaller, reusing the same models you already made?

No, no, I don't ever do that.

[WarriorSabe]

1 hour ago, Nertea said:

No, no, I don't ever do that.

Why not? I'm just talking about simple fuel tanks, not engines or antimatter storage.

[Nertea]

It breaks the texel density. 

[RedParadize]

Humm... I tried several times to harvest He3 from Jool using atmo scoop. I barely succeeded at going bellow the altitude and speed limit of scooping alive and have yet to figure out how to go back to orbit again. I do not think its possible to extract it economically, at least at 6.4 scale.

Edit: I did it! I just need to get to just above the atmo and drop speed by +-9000m/s Then I could use the scooper to fill up and regain them to get back to orbit.

Edit2: Sad face.  Bussard Particle scoop Isn't picking up enough hydrogen to feed my Jool He3 atmospheric scoop. At any rate, reactor will run out way before I get any significant amount of Hydrogen.

Edited November 15, 2020 by RedParadize

[Cochies]

Experimented with a Fresnel engine.
It seems to me that the impulse in the "reaction products" mode should be raised to 160,000 - 300,000, depending on the length. So the "high thrust / low delta" and "high delta / low thrust" modes will start to work logically in terms of gameplay, but will leave the Hammertong engine more efficient in terms of delta.

Clarke's engine thrust, it seems to me, needs to be reduced, and reduced greatly. With a max thrust of about 10 kN this is a good simple solution for lightweight probes. Now it is too simple, it even works with heavy ships and occupies the Hammertong niche. (Oh yeah, you moved it to node 4000! Great!)

I also wanted to ask: is it possible to disable the waterfall debug menu in the right pane? It's good that there is such a menu, but it is unlikely that you need it all the time in flight))))

UPD:

And there is a small problem with HeathSystem.
When the battery is full, the reactors run at 25% power and very slowly increase power when the charge is expended.
This is an interesting mechanic, but when such reactors are used with NFP motors it leads to problems.
When the engines are turned on, the reactor does not have time to gain power from 25% to 100% and the energy is spent too quickly.
You need to increase thrust very slowly or have huge batteries. It is not convenient for flying.
It might be nice to be able to manually increase the power to 100% before starting the engines.

Edited November 15, 2020 by Cochies

[CDSlice]

7 hours ago, RedParadize said:

Humm... I tried several times to harvest He3 from Jool using atmo scoop. I barely succeeded at going bellow the altitude and speed limit of scooping alive and have yet to figure out how to go back to orbit again. I do not think its possible to extract it economically, at least at 6.4 scale.

It sounds like the resource definitions aren't being scaled with the planets to me. I'm not sure if it would be on Sigma or FFT to handle that though.

[RedParadize]

54 minutes ago, CDSlice said:

It sounds like the resource definitions aren't being scaled with the planets to me. I'm not sure if it would be on Sigma or FFT to handle that though.

I actually tested it without atmo scaling, the intake start working at a proportionally equal alt with the scaled version. I do not think that's a issue.  Its just much more harder on higher scale and that's it.

I managed to it with this thing:


It can extract about 6300 He3 and 4200 Deuterium per dive, that isn't bad at all, but to make sense that thing need to be reused. Problem I now have is that getting out of Jool leave the plane almost out of Hydrogen. I need 8k dV to break before diving, otherwise I burn. I need to extract Hydrogen elsewhere.

Bussard Particle scoop seem to pick up some hydrogen particle in Jool orbit, but from want I can see it would take many, many years to pick what I need. Probably much more than nuclear reactor lifespan. Other than that, there is the water of Laythe that I could convert, but that wont be cheap. Either way it would cost multiple millions for a marginal gain. Its cheaper to ship hydrogen from Kerbin using Fission fragment, for sure. That's weird, isn't it?

Ps: Engine I used a scaled down JR20A, with the regular one the plane would most likely need to be twice as big, so it would need even Hydrogen to run.

Edited November 15, 2020 by RedParadize

[RedParadize]

Welp, looks like I did not need atmospheric engine after all, Discovery can do it if I do not get too low:

[Nertea]

11 hours ago, RedParadize said:

Humm... I tried several times to harvest He3 from Jool using atmo scoop. I barely succeeded at going bellow the altitude and speed limit of scooping alive and have yet to figure out how to go back to orbit again. I do not think its possible to extract it economically, at least at 6.4 scale.

Edit: I did it! I just need to get to just above the atmo and drop speed by +-9000m/s Then I could use the scooper to fill up and regain them to get back to orbit.

Edit2: Sad face.  Bussard Particle scoop Isn't picking up enough hydrogen to feed my Jool He3 atmospheric scoop. At any rate, reactor will run out way before I get any significant amount of Hydrogen.

This probably needs some tuning, but I am not really intending compatibility with a 6.4x rescale. The goal would be to get it playable at stock scales and then move on. 

7 hours ago, Cochies said:

It seems to me that the impulse in the "reaction products" mode should be raised to 160,000 - 300,000, depending on the length. So the "high thrust / low delta" and "high delta / low thrust" modes will start to work logically in terms of gameplay, but will leave the Hammertong engine more efficient in terms of delta.

Can you explain what is not logical right now? The reaction products mode is 60-200ks, and the other is 12-40ks. 

7 hours ago, Cochies said:

I also wanted to ask: is it possible to disable the waterfall debug menu in the right pane? It's good that there is such a menu, but it is unlikely that you need it all the time in flight))))

Make sure you have the latest release, it is disabled by default.

7 hours ago, Cochies said:

Clarke's engine thrust, it seems to me, needs to be reduced, and reduced greatly. With a max thrust of about 10 kN this is a good simple solution for lightweight probes. Now it is too simple, it even works with heavy ships and occupies the Hammertong niche. (Oh yeah, you moved it to node 4000! Great!)

 

Yes it is getting a nerf bat in next release in terms of thrust. 

7 hours ago, Cochies said:

And there is a small problem with HeathSystem.
When the battery is full, the reactors run at 25% power and very slowly increase power when the charge is expended.
This is an interesting mechanic, but when such reactors are used with NFP motors it leads to problems.
When the engines are turned on, the reactor does not have time to gain power from 25% to 100% and the energy is spent too quickly.
You need to increase thrust very slowly or have huge batteries. It is not convenient for flying.
It might be nice to be able to manually increase the power to 100% before starting the engines.

Yes I am working on this (see the SystemHeat thread). Don't have a solution I like yet. 

 

 

 

 

[Cochies]

2 hours ago, Nertea said:

This probably needs some tuning, but I am not really intending compatibility with a 6.4x rescale. The goal would be to get it playable at stock scales and then move on. 

Can you explain what is not logical right now? The reaction products mode is 60-200ks, and the other is 12-40ks. 

Make sure you have the latest release, it is disabled by default.

Yes it is getting a nerf bat in next release in terms of thrust. 

Yes I am working on this (see the SystemHeat thread). Don't have a solution I like yet. 

 

 

 

 

Waterfall updated, thanks)

The problem with fresnel is somewhat:
1 - now the balance is such that the "low thrust" mode makes it possible to build a propulsion system of about the same mass as the installation in the "reaction products" mode, with a close delta-V, but with a better TWR.

RP: 100 tons load, 50 tons propulsion system, 31000 delta. 0.05 TWR, price over 2.5 million

LT: 100 tons of load, 75 tons of the propulsion system, 21,000 deltas and as much as 0.2 TWR - which makes it easy to increase the fuel reserve and have the same 30,000 delta, but with TWR 0.15.
And the price is about 1.5 million

What choice will 99% of players make?

2 - the "reaction products" setting will be much more expensive because of the expensive fuel.
3 - "reaction products" setting requires much more radiators
4 - setting the "reaction products" fresnel engine has less impulse than the less perfect Hammertong. Why?

In general, it seems to me, the player does not get the feeling that he has a reasonable choice between two good, but different modes. There is a good mode. And bad.

160,000 impulses on a 6-meter RP-Fresnel will give about 80,000 delta. Yes, the TWR is not big, but 80,000 is not 30,000 at all.
You might really want to use this mode.


Speaking about the problem of nuclear reactors, raising ThrottleIncreaseRate to 5-7 still requires attention to the throttling of reactors, but already allows them to be comfortably used in propulsion systems.
This may not be the best solution, but why not?

Edited November 15, 2020 by Cochies

[Nertea]

22 hours ago, Cochies said:

The problem with fresnel is somewhat:
1 - now the balance is such that the "low thrust" mode makes it possible to build a propulsion system of about the same mass as the installation in the "reaction products" mode, with a close delta-V, but with a better TWR.

RP: 100 tons load, 50 tons propulsion system, 31000 delta. 0.05 TWR, price over 2.5 million

LT: 100 tons of load, 75 tons of the propulsion system, 21,000 deltas and as much as 0.2 TWR - which makes it easy to increase the fuel reserve and have the same 30,000 delta, but with TWR 0.15.
And the price is about 1.5 million

What choice will 99% of players make?

2 - the "reaction products" setting will be much more expensive because of the expensive fuel.
3 - "reaction products" setting requires much more radiators
4 - setting the "reaction products" fresnel engine has less impulse than the less perfect Hammertong. Why?

In general, it seems to me, the player does not get the feeling that he has a reasonable choice between two good, but different modes. There is a good mode. And bad.

160,000 impulses on a 6-meter RP-Fresnel will give about 80,000 delta. Yes, the TWR is not big, but 80,000 is not 30,000 at all.
You might really want to use this mode.

Thanks for the details, definitely making some changes next update. 

[Starhelperdude]

Will the new Antimatter Engine be a pulse engine or a ''continous thrust'' engine?

[SpaceFace545]

8 hours ago, Starhelperdude said:

Will the new Antimatter Engine be a pulse engine or a ''continous thrust'' engine?

Probably a pulse for the animation but in game it doesn’t matter.

[Nertea]

Continuous. 

[Nertea]

Last part for this update: the antimatter factory. Feed really high amounts of power and cooling, get antimatter from various feedstocks. Probably best to ship these out to Moho orbit with big solar panels. Shipping it will be a challenge though, it's probably going to weigh 100-150t and is pretty massive (size of a mid-size Fresnel).

Unwrap's done, working on the texture now.

Once this part is ingame I will push out a new update

[toric5]

OOOH! lots and lots of pipes!

Edited November 18, 2020 by toric5

[WarriorSabe]

3 hours ago, Nertea said:

Last part for this update: the antimatter factory. Feed really high amounts of power and cooling, get antimatter from various feedstocks. Probably best to ship these out to Moho orbit with big solar panels. Shipping it will be a challenge though, it's probably going to weigh 100-150t and is pretty massive (size of a mid-size Fresnel).

So basically a big linac to put on your ships?

[SpaceFace545]

could i just put this on the ground or are there limitations.

[Nertea]

8 hours ago, WarriorSabe said:

So basically a big linac to put on your ships?

It's actually closer to the recent experiments that have been generating electron/positron pairs by illuminating elementary particle targets with petawatt laser beams. Supposedly the physics extends such that if you had more powerful lasers, you could generate proton/antiproton pairs similar to how antipropotons are currently generated in high energy collisions, but without the need for an accelerator +decelerator ring. So, I modeled a very large laser facility somewhat after the NIF.

4 hours ago, SpaceFace545 said:

could i just put this on the ground or are there limitations.

You can put it wherever you want as long as you can supply the power and cooling needs. 

[toric5]

1 hour ago, Nertea said:

It's actually closer to the recent experiments that have been generating electron/positron pairs by illuminating elementary particle targets with petawatt laser beams. Supposedly the physics extends such that if you had more powerful lasers, you could generate proton/antiproton pairs similar to how antipropotons are currently generated in high energy collisions, but without the need for an accelerator +decelerator ring. So, I modeled a very large laser facility somewhat after the NIF.

'illuminating' is a strangely peaceful word choice to come just before 'petawatt laser beams'