FreeThinker

[1.8.1, 1.7.3/1.6.1/1.5.1/1.4.5] KSP Interstellar Extended 1.25 Continued Development Thread

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6 minutes ago, raxo2222 said:

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

Yes, but you can also figure it out by strapping a reactor to an engine and putting all propellants in various fuel tanks to test it out yourself. I dont have exact numbers, but heres a basic rundown (excluding nuclear engines)

ATTILA: -------------------------Lqd Methane
Magneto Plasma: ---------------Lqd Krypton
T. Turbojet: ---------------------Lqd Methane 
T. Ramjet: ----------------------Lqd Methane
Krusader: -----------------------Lqd Methane
Wakefield: -----------------------Lqd Krypton
Plasma Noz: -------------------Lqd Methane

Now none of these propellants have the highest ISP, but they have (in my opinion) the best performance when considering mass and volume. LqdMethane is awesome because it has a thrust multiplier for thermal engines due to its expansive properties when heated, and it retains good ISP because it is a light molecule. LqdKrypton is a good electric engine propellant because it has a higher ISP than Xenon, costs a lot less, and has the highest fuel efficiency rating. 

Unfortunately i did not test the vasmir engines because... well i haven't had to yet. 

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10 minutes ago, raxo2222 said:

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

I will make the electric engine module info more informative

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1 minute ago, FreeThinker said:

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.

Then i look forward to seeing how it performs :cool:

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5 minutes ago, FreeThinker said:

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.

Ok, that's a pretty nifty advantage.

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19 minutes ago, secretly_asian said:

Yes, but you can also figure it out by strapping a reactor to an engine and putting all propellants in various fuel tanks to test it out yourself. I dont have exact numbers, but heres a basic rundown (excluding nuclear engines)

ATTILA: -------------------------Lqd Methane
Magneto Plasma: ---------------Lqd Krypton
T. Turbojet: ---------------------Lqd Methane 
T. Ramjet: ----------------------Lqd Methane
Krusader: -----------------------Lqd Methane
Wakefield: -----------------------Lqd Krypton
Plasma Noz: -------------------Lqd Methane

Now none of these propellants have the highest ISP, but they have (in my opinion) the best performance when considering mass and volume. LqdMethane is awesome because it has a thrust multiplier for thermal engines due to its expansive properties when heated, and it retains good ISP because it is a light molecule. LqdKrypton is a good electric engine propellant because it has a higher ISP than Xenon, costs a lot less, and has the highest fuel efficiency rating. 

Unfortunately i did not test the vasmir engines because... well i haven't had to yet. 

Useful to know. I'll have to test these later.

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Thermal engines seemed to have highest thrust and DV in same volume with Hydrazine.

 

Since electric engines will get thrust boost with some techs, will ARCJET engine get thrust boost too?

Its most compact way to have hovercraft, but it produces ton of wasteheat.

Edited by raxo2222

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1 minute ago, raxo2222 said:

Thermal engines seemed to have highest thrust with Hydrazine.

what was its ISP? i dont remember if hydrazine was one of the three fuels that has the same properties as methane, i do know ammonia has that.

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Just now, secretly_asian said:

what was its ISP? i dont remember if hydrazine was one of the three fuels that has the same properties as methane, i do know ammonia has that.

If it wasn't changed then it was 0.7x - 0.75x of Hydrogen ISP.

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5 minutes ago, raxo2222 said:

If it wasn't changed then it was 0.7x - 0.75x of Hydrogen ISP.

I just ran a test using the thermal nozzles utilizing beamed power and the thermal receiver. on a 3.75m formfactor, a thermal nozzle using Lqd Methane and receiving 10GW of beamed energy has an ISP of 905s and ~3600 KN of thrust. When I used Hydrazine I had ~510s ISP and ~1200KN thrust. 

 

Not only is Methane lighter, it is also non-toxic (ish)! 

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48 minutes ago, secretly_asian said:

I just ran a test using the thermal nozzles utilizing beamed power and the thermal receiver. on a 3.75m formfactor, a thermal nozzle using Lqd Methane and receiving 10GW of beamed energy has an ISP of 905s and ~3600 KN of thrust. When I used Hydrazine I had ~510s ISP and ~1200KN thrust. 

 

Not only is Methane lighter, it is also non-toxic (ish)! 

I guess it was changed after all.

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1 hour ago, secretly_asian said:

Not only is Methane lighter, it is also non-toxic (ish)! 

1

Yes but its not clean when used in a thermal nozzle, as it slowly clogs up the heat exchangers due to produced soot sticking to everything, causing the engine to degrade in maximum thrust.  The soothing can actually be a good thing if you want to produce Buckyballs ;)

Edited by FreeThinker

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20 hours ago, secretly_asian said:

beamed energy has an ISP of 905s and ~3600 KN of thrust. When I used Hydrazine I had ~510s ISP and ~1200KN thrust.

 

Lol, that Methane thrust looks too high, looking at it again I have spotted a math mistake (I forgot to add brackets)  :sealed:

Edited by FreeThinker

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39 minutes ago, FreeThinker said:

Lol, that Methane thrust looks too high, looking at it again I have spotted a math mistake, I forgot to add a brackets

Now you can check for mistakes in other places :p

 

Is there any difference in thrust if I use plasma nozzle or thermal nozzle?

Edited by raxo2222

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1 hour ago, raxo2222 said:

Is there any difference in thrust if I use plasma nozzle or thermal nozzle?

Plasma nozzle has unrestricted Isp, but is not suitable for atmospheres except when powered by positron reactor. You usually use it with high temperature reactors like the Open Cycle Gas Core reactor, Magnetic Confinement Fusion reactor, Plasma Jet Magneto Inertial Fusion Reactor and of course the Positron Antimatter Reactor.

Edited by FreeThinker

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2 hours ago, FreeThinker said:

Plasma nozzle has unrestricted Isp, but is not suitable for atmospheres except when powered by positron reactor. You usually use it with high temperature reactors like the Open Cycle Gas Core reactor, Magnetic Confinement Fusion reactor, Plasma Jet Magneto Inertial Fusion Reactor and of course the Positron Antimatter Reactor.

Antimatter Initiated Fusion reactor is good too - it has highest power density of all reactors not counting QSR/pure antimatter without and with builtin engine at given radius.

 

You can use diamagnetic antimatter container as way to store positrons.

2.5m can store 106 kg of antimatter that is 57g of positrons.

Can I use antimtter reactor to make positrons?

106 kg of antiproton isn't too useful in that case :p

Or those antiprotons can be used for magnetic nozzle :p

LCMTt50.jpg

CQFxBHP.jpg

 

Magnetic nozzle is so efficient that is uses more hydrogen than antimatter :p

Edited by raxo2222

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15 hours ago, FreeThinker said:

Lol, that Methane thrust looks too high, looking at it again I have spotted a math mistake, I forgot to add a brackets

How high is it supposed to be?!?! Atmospheric mode on the thermal jet is like 7800 kn @ 350s when its scaled to 3.75 with a 10GW beamed power supply

[I PM'ed you]

 

 

Edited by secretly_asian

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Next release will reintroduce the "Discovery" Magnetic Confinement Fusion Rocket

WBdDJGp.jpg

It will be unlocked at Advanced Fusion Rockets, at the same tech level (2250 sci) as the Open Cycle Nuclear Gas Core Engine.

Edited by FreeThinker

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I think you misread something - I meant dynamic pressure divided by 10 + static pressure,  not whole thing divided by 10 when calculating max temp of radiator.

oxidationModifier = Math.Sqrt(vessel.staticPressurekPa + vessel.dynamicPressurekPa) / 10;

should be

oxidationModifier = Math.Sqrt(vessel.staticPressurekPa + vessel.dynamicPressurekPa/ 10);

@FreeThinker

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31 minutes ago, raxo2222 said:

I think you misread something - I meant dynamic pressure divided by 10 + static pressure,  not whole thing divided by 10 when calculating max temp of radiator.

oxidationModifier = Math.Sqrt(vessel.staticPressurekPa + vessel.dynamicPressurekPa) / 10;

should be

oxidationModifier = Math.Sqrt(vessel.staticPressurekPa + vessel.dynamicPressurekPa/ 10);

@FreeThinker

 

Well, I have to admit I haven't had the time to test this out yet fully but the general idea is that when standing on the surface of Kerbin, the formula would result in 1 (Sqrt(100) / 10 = 1) and that dynamic pressure is threaded as an increase to normal pressure. Ideally we replace it by a more scientifically accurate function but for gaming purposes, an approximation is often enough

Edited by FreeThinker

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37 minutes ago, FreeThinker said:

Well, I have to admit I haven't had the time to test this out yet fully but the general idea is that when standing on the surface of Kerbin, the formula would result in 1 (Sqrt(100) / 10 = 1) and that dynamic pressure is threaded as an increase to normal pressure. Ideally we replace it by a more scientifically accurate function but for gaming purposes, an approximation is often enough

So it would be like this?  oxidationModifier = Math.Sqrt(vessel.staticPressurekPa + vessel.dynamicPressurekPa/10) /10 ?

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10 minutes ago, raxo2222 said:

So it would be like this?  oxidationModifier = Math.Sqrt(vessel.staticPressurekPa + vessel.dynamicPressurekPa/10) /10 ?

Yes, possibly, but I first need to understand how dynamicPressurekPa grows with vessel speed. How fast do you have to go before you achieve 100kP of dynamic pressure? If the speed is about 300 m/s (the speed of sound) then we don't have to do anything, it, if it's much larger, we have to multiply it, only if its much bigger be need to divide it. My understanding of KSP physics model for dynamic pressure is insufficient.

Edited by FreeThinker

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15 hours ago, raxo2222 said:

Can I use antimtter reactor to make positrons?

2

Technically it should already do that when you feed your beam core antimatter reactor from a dielectric antimatter container. the Beam core only uses the ANtiproton, the positron is discarded or stored in a positron storage container when available.

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32 minutes ago, FreeThinker said:

Yes, possibly, but I first need to understand how dynamicPressurekPa grows with vessel speed. How fast do you have to go before you achieve 100kP of dynamic pressure? If the speed is about 300 m/s (the speed of sound) then we don't have to do anything, it, if it's much larger, we have to multiply it, only if its much bigger be need to divide it. My understanding of KSP physics model for dynamic pressure is insufficient.

On wikipedia dynamic pressure is density [kg/m^3] * speed squared (m/s)^2 and divided by two.

1/2 * density*speed^2

I used density of 1 - speed would be around 450 m/s on sea level.

Both stock and FAR should use this equation for dynamic pressure.

 

I wanted to divide dynamic pressure because radiators most of time are almost parallel that is up to 15 degrees to air flow.

--------- radiators  <--------------------incoming air (slightly angled most of time)

Only during reentry radiator would be placed like this:

\  <----------------- Air

Edited by raxo2222

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15 hours ago, raxo2222 said:

You can use diamagnetic antimatter container as way to store positrons.

2.5m can store 106 kg of antimatter that is 57g of positrons.

2

Yes that would work but be highly wasteful and expansive. Instead, I'm considering introducing a new resource call positronium, which would be electrically neutral and can, therefore in theory, be stored at higher densities than electric static positron storage containers. Perhsps could be stored in some sort of Bose–Einstein condensate stap.

Edited by FreeThinker

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1 minute ago, FreeThinker said:

Yes that would work but be highly wasteful and expansive. Instead, I'm considering introducing a new resource call positronium, which would be electrically neutral and can, therefore, be stored at higher densities than electric static containers. I just have no idea how that would work.

Some not yet discovered physics, that makes QSR, mach effect and warp drive work.

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