KSP Interstellar Extended Continued Development Thread

[FreeThinker]

Version 1.19.11 for Kerbal Space Program 1.4.5 can now available from here

Released on 2018-09-12

• Compiled against KSP 1.4.5
• Fixed hiding of unnecessary buttons in Radiator
• Fixed linear behavior of thermal nozzle throttle and trust percentage
• Fixed radiators convection when on the surface
• Fixed thermal nozzle calculated field when generating thrust
• Fixed Thermal Receiver compatibility with Thermal Nozzles

Edited September 12, 2018 by FreeThinker

[FreeThinker]

On 9/10/2018 at 9:51 AM, raxo2222 said:

Ah so wakefield isn't for lower atmospher.

3

Considering it has a very large magnetic throat where the external static pressure has to be overcome, you are correct. For atmospheres you best use turbo or ram jet nozzles which can convert intake air directly into thrust. An electrical alternative might be an ATILLA which has throat more suitable for atmospheres.

On 9/10/2018 at 9:51 AM, raxo2222 said:

Basically I have to climb out to 25 - 30 km for graphene radiators to be effective

1

Yes, Graphene radiators is essentially graphite in more stable configuration, but still can catch fire in an oxygen atmosphere when heat high enough. To compensate use convection radiators, or replace the graphene radiators by non-graphene radiators.

 

On 9/10/2018 at 9:51 AM, raxo2222 said:

Wakefield for full thrust needs 30 GW, but my setup provides only 16 GW of power or so - Antimatter Fusion is most energy dense reactor not counting antimatter ones.

 

It is indeed the most powerful fusion reactor. It is one of the few capable of providing both changed and thermal power externally. The obvious disadvantage is that it is near the end of the tech tree and require expansive and hard to store fuels. Notice That to Maximise electric power output, you need to connect it to MHD power generator, as it charged particle power utilisation is capped at 50%.

Edited September 14, 2018 by FreeThinker

[FreeThinker]

On 9/10/2018 at 9:51 AM, raxo2222 said:

I added two thermal turbojets with thermal fusion engines on wing tips and moved atmospheric collector to bottom - I used procedual parts for connecting things.

1

A smarter solution would be to feed turbojet directly from an Antimatter Fusion Engine. I prefer to do it radially in X wing configuration, which will move more mass to the centre of the vessel. This will save both cost and mass, which is always a good thing.

[raxo2222]

2 hours ago, FreeThinker said:

It is indeed the most powerful fusion reactor. It is one of the few capable of providing both changed and thermal power externally. The obvious disadvantage is that it is near the end of the tech tree and require expansive and hard to store fuels. Notice That to Maximise electric power output, you need to connect it to MHD power generator, as it charged particle power utilisation is capped at 50%.

So can I use remaining charged particle potential for MHD?

If I get two generators, then how I can use plasma engine?

Its directly connected to reactor.

 

Why Mach Effect drive doesn't use full potential of reactor?

At its size it should use up to 50 GW of power.

Thermal efficiency is ~90% here.

Maybe propellant efficiency shouldn't reduce maximum power usage?

That is propellant efficiency doesn't reduce thrust directly, but it reduces power usage.

That happens with all electrical engines.

Edited September 14, 2018 by raxo2222

[FreeThinker]

5 hours ago, raxo2222 said:

So can I use remaining charged particle potential for MHD?

If I get two generators, then how I can use plasma engine?

1

No the MHD generator kind of a Thermal Generator and Charged Particle Generator into one. It utilizes all available thermal and charged particle energy available in a reactor. Its efficiency depends on a combination of reactor core temperature and fuel charged particle ratio. It works best with reactors where the reactor produces plasma, a mix of thermal and charged particle energy.

5 hours ago, raxo2222 said:

Why Mach Effect drive doesn't use full potential of reactor?

3

The Mach drive is not like any other electric engine. It can generate thrust in any direction without exhaust or needing any propellant. Its main limitation is that its thrust is limited by its mass density. So even if you had a lot of power and cooling capacity, it would simply not be able to generate more thrust and instead rip itself apart. A possible way around this would be to use a  black hole ...

Edited September 14, 2018 by FreeThinker

[FreeThinker]

5 hours ago, raxo2222 said:

Thermal efficiency is ~90% here.

Maybe propellant efficiency shouldn't reduce maximum power usage?

 

These values are mainly meant for internal usage and don't mean anything for comparison with other electric engines

[raxo2222]

4 minutes ago, FreeThinker said:

These values are mainly meant for internal usage and don't mean anything for comparison with other electric engines

Then it has confusing maximum power consumption  entry.

Well that is happening with other engines - they will use different amount of power with different propellants at given thermal efficiency.

VASMIR will consume less power at 100% than at 10%, as at 100% is ~30% efficient and at 10% it has 66% propellant efficiency.

[FreeThinker]

8 minutes ago, raxo2222 said:

lt uses different amount of power with different propellants at given thermal efficiency.

VASMIR will consume less power at 100% than at 10%, as at 100% is ~30% efficient and at 10% it has 66% propellant efficiency.

3

Correct it become less electric efficient at lower isp/throttle setting.

[raxo2222]

24 minutes ago, FreeThinker said:

Correct it become less electric efficient at lower isp/throttle setting.

So lower propellant efficiency means lower power consumption?

Why is that? Can't power consumption be constant and just lower thrust when propellant efficiency is lower?

Edited September 14, 2018 by raxo2222

[FreeThinker]

I'm going to attempt to improve the description of parts, any help would be appreciated:

Thermal Power Generator: A Thermal Power Generator that turns reactor Thermal power into electrical power. Efficiency depends on the availability of radiators. Use thermal helper in VAB to determine how much radiators needed for optimum performance. To function the generator needs to be connected directly to thermal power reactor. Mass of the generator depends on the connect reactor and its configured utilisation, which can be set in the Editor. Connecting a reactor with more than one thermal generator, will not work. Note that some reactors are not compatible with a Thermal Power Generator or already have an integrated thermal generator. This information can be found in the reactors modules information.

MHD Generator: A Magnetohydrodynamic generator converts plasma energy directly into electric power. It needs to be connected directly to a reactor to function. It cannot function concurrently with either a thermal power generator or charged particle power generator. An MHD generator efficiency depends on a combination of the radiator temperature, core reactor temperature, charged particle percentage and unlocked plasma technology.

 

 

 

30 minutes ago, raxo2222 said:

So lower propellant efficiency means lower power consumption?

Why is that? Can't power consumption be constant and just lower thrust when propellant efficiency is lower?

No, due to the lower efficiency maximum power consumption decreases

Edited September 14, 2018 by FreeThinker

[raxo2222]

What charged particle energy percentage is best for MHD? 50%?

[FreeThinker]

5 minutes ago, raxo2222 said:

What charged particle energy percentage is best for MHD? 50%?

Maximum theoretical efficiency is 80%.

Edited September 14, 2018 by FreeThinker

[raxo2222]

7 minutes ago, FreeThinker said:

Maximum theoretical efficiency is 80%.

I meant what ratio of thermal energy to charged particles is best for MHD.

[FreeThinker]

7 hours ago, raxo2222 said:

Why Mach Effect drive doesn't use full potential of reactor?

3

Notice the Mach Effect drive can also function in RCS mode, which is ideal for docking with space stations

1 minute ago, raxo2222 said:

I meant what ratio of thermal energy to charged particles is best for MHD.

Well 100% of charged particle course, but in that case, it is usually better to use a charged particle direct converter, which achieves efficiencies up to 95%

[raxo2222]

18 hours ago, FreeThinker said:

Notice the Mach Effect drive can also function in RCS mode, which is ideal for docking with space stations

Well 100% of charged particle course, but in that case, it is usually better to use a charged particle direct converter, which achieves efficiencies up to 95%

So I guess there is point where MHD is better than having both charged/thermal generators.

There should be way to find if in given situation you are better of with MHD or with Thermal/Charged combo.

 

Isn't max temp for graphene radiators raising too fast?

There still is substantial atmosphere at this altitude.

Edited September 15, 2018 by raxo2222

[FreeThinker]

Next  release will introduce more realistic behavior  of ion and thermal engine in atmosphere and proper integration of stock ion engine

Also next release will introduce capacity upgrading for electric engines, which effect can be quite dramatic.

Initially the stock Ion engine will only have a maximum capacity of only 2 Newton (which is realistic), only after unlocking extreme electric systems  it will be able to produce a whooping 2 kilo Newton (which is extreme).

 

 

Edited September 16, 2018 by FreeThinker

[FreeThinker]

On 9/14/2018 at 7:33 PM, raxo2222 said:

Isn't max temp for graphene radiators raising too fast?

There still is substantial atmosphere at this altitude.

Good point, I guess I could apply some square root function here like

TemperatureRatio = Sqrt(StaticPresurureInKn) / 10

 

[raxo2222]

1 hour ago, FreeThinker said:

Good point, I guess I could apply some square root function here like

TemperatureRatio = Sqrt(StaticPresurureInKn) / 10

 

It should be independent from actual max temperature of graphene radiator, that is at given pressure max radiator temperature would be always X kelvins.

Or is it already case?

That is at certain pressure max radiator temperature is 2000 K and at other pressure max radiator temperature is 3000 K no matter what heat upgrades radiator has?

By the way dynamic pressure should be taken in account too.

For ease it could be simply divided by some value (or be dependent on angle of attack of radiator)  and added to static pressure.

It would be something like total pressure = static pressure + dynamic pressure/10 (or possibly include angle of attack of whole space ship/single radiators too)

Edited September 16, 2018 by raxo2222

[SpaceMouse]

*disregard post*

Edited September 18, 2018 by SpaceMouse

[FreeThinker]

I discovered a very interesting new type of propellant called buckminsterfullerene, aka Buckyballs. It appears to well suited as an electrical propellant. Its a nano molecule consisting out of 60 Carbon atoms, is very stable, easy to turn into a gas, easy ionize, and has potentially a high storage density and generates almost twice amount of thrust (and half the isp) compared to Xenon.

I intend to add is as an advanced ion engine propellant and to the IFS storage container as a configuration next release

Edited September 19, 2018 by FreeThinker

[SpaceMouse]

1 hour ago, FreeThinker said:

I discovered a very interesting new type of propellant called buckminsterfullerene, aka Buckyballs. It appears to well suited as an electrical propellant. Its a nano molecule consisting out of 60 Carbon atoms, is very stable, easy to turn into a gas, easy ionize, and has potentially a high storage density and generates almost twice amount of thrust (and half the isp) compared to Xenon.

I intend to add is as an advanced ion engine propellant and to the IFS storage container as a configuration next release

You know, more propellant options are cool but, are the 20 or so different ones really needed? the ISP vs. thrust difference mostly seems to balance out for most.

[secretly_asian]

1 hour ago, FreeThinker said:

I discovered a very interesting new type of propellant called buckminsterfullerene, aka Buckyballs. It appears to well suited as an electrical propellant. Its a nano molecule consisting out of 60 Carbon atoms, is very stable, easy to turn into a gas, easy ionize, and has potentially a high storage density and generates almost twice amount of thrust (and half the isp) compared to Xenon.

I intend to add is as an advanced ion engine propellant and to the IFS storage container as a configuration next release

Unless this new propellant is really really unique in a way, i'm sticking to Lqd Methane and Lqd Krypton as my two primary propellants. 

[SpaceMouse]

20 minutes ago, secretly_asian said:

Unless this new propellant is really really unique in a way, i'm sticking to Lqd Methane and Lqd Krypton as my two primary propellants. 

I feel like FreeThinker likes to make life harder than it needs to be. 

[raxo2222]

It would be nice to have list of all propellants, that engines can use and their multipliers on efficiency, thrust and ISP.

[FreeThinker]

2 hours ago, secretly_asian said:

Unless this new propellant is really really unique in a way, i'm sticking to Lqd Methane and Lqd Krypton as my two primary propellants. 

Yes it is really unique as, as it uses an element (carbon) that can be found almost anywhere, stored as a high density solid at room temperatures as an electric propellant. There is no other propellant with those characteristics.