FreeThinker

[1.7.3/1.6.1/1.5.1/1.4.5/1.3.1] KSP Interstellar Extended 1.23.8 Continued Development Thread

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1 hour ago, Eleusis La Arwall said:

Nothing in particular. It's more a space-filler - just the round sphere looked a little boring :D I use these quite often and sometimes I like to see them as kind of pumps. In this case maybe for the coolant and/or the propellant if used as engine. Maybe retaining bolts but they are a bit too big.
I'm thankfull for any input!

alright, It appears there is a beam slicing through the reactor core which needs to be a perfect sphere internally to perform well, therefore I suggest you curve the beam around the sphere no through it.

Edit. also can you make the sphere a bit bigger? The ball structure should realy be the thing that defines this part.

Edited by FreeThinker

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220px-Gas_Core_open_cycle.png

 

Oh notice the blue pipe on the bottum, it means there should be some conduits going from the back to the front.

 

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1 hour ago, Eleusis La Arwall said:

Removed the struts completly and added some other stuff. How about this:
cNpuA0B.png
Two sides have pipes and two sides are free.

Much sleeker!

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On 18-11-2016 at 5:38 PM, Nansuchao said:

Much sleeker!

Indeed, but I'm still not satisfied about those stubs on the sphere. Perhaps we can move them to the base and head instead, than their pumping functionality would be more logical.

Edited by FreeThinker

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2 questions:

What engine in what mode gives you most thrust per megawatt of reactor power - most kN/MW.

Megawatt is megawatt, doesn't matter if its raw thermal energy from fission reactor, charged particles from fusion reactor or electricity from exotic reactor.

What engine/reactor combination has highest TWR per ton of combined reactor/generator/engine mass?

For example I picked this engine and that reactor (with generator if its fusion reactor or electrical engine) or engine with built in reactor and for example it has TWR of 1.0

 

Edited by raxo2222

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43 minutes ago, FreeThinker said:

@raxo2222 In terms of pure TWR rating, the particle bed reactor, a.k.a the Timberwind engines are the most powerful until the advent of antimatter reactors

So Timberwind requires lowest mass of engine/reactor/generator/radiator/reactor fuel tank complex to achieve given thrust. (kN of thrust per ton of engine complex), right?

On other end there is EM drive with probably lowest kN/ton performance.

And what engine is best at converting megawatts of power to kiloNewtons of thrust? Standalone Thermal Turbojet? Rocket launch nozzle? Engine with builtin reactor?

What propellant is best for each engine, when it comes to converting power to thrust?

Is kN/MW ratio same for given engine and propellant, when it comes to size and type for engine/reactor complex?

Is 1 MN of thrust per MW of power engine/reactor complex even possible?

 

Edited by raxo2222

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Well every reactor has it niche or can cover a wide range of roles. When it comes to producing high amount of power efficiently a Stellarator is quite good, but if you want to produce it for a very long time an aneutronic Colliding Beam Core can do it considerable longer and cheaper. But if you want to have decent amount of thrust, you need a Magnetized Fusion Reactor, but if that not efficient enough, a Magneto Inertial Fusion engine is you friend and if you want to be get even more efficient, you should use a Magnetic Nozzle on a Tokamak, but if you need to travel to another star your going to need a Deadalus Inertial Confinement Fusion engine which of unfortunately is very expansive due to the high cost of it fuel, a much cheaper alternative would be a EM drive, but you need an efficient reactor to power it. It hope you get point, there aint no best reactor, it rally comes down to context and personal preference, and that a good thing I think.

Edited by FreeThinker

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11 hours ago, FreeThinker said:

Well every reactor has it niche or can cover a wide range of roles. When it comes to producing high amount of power efficiently a Stellarator is quite good, but if you want to produce it for a very long time an aneutronic Colliding Beam Core can do it considerable longer and cheaper. But if you want to have decent amount of thrust, you need a Magnetized Fusion Reactor, but if that not efficient enough, a Deadalus Magneto Inertial Fusion engine is you friend and if you want to be get even more efficient, you should use a Magnetic Nozzle on a Tokamak, but if you need to travel to another star your going to need a Inertial Confinement Fusion engine which of unfortunately is very expansive due to the high cost of it fuel, a much cheaper alternative would be a EM drive, but you need an efficient reactor to power it. It hope you get point, there aint no best reactor, it rally comes down to context and personal preference, and that a good thing I think.

I'm not asking for best reactor, I'm asking for engine that has best thrust per MW of power.

I tested all fission engines with built-in reactors.

Assuming, that kN/MW performance doesn't change with size/upgrade level of engine and propellant has flat thrust multiplier regardless of engine/reactor combination.

Using Hydrogen, as all engines use this propellant except EM Drive.

http://imgur.com/a/AKIf5

 

Here are 2 engines with builtin fusion reactors:

http://imgur.com/a/tADGG

 

3 thermal engines connected to molten salt reactor.

http://imgur.com/a/SOWTP

 

2 charged particle engines connected to MFC fusion reactor:

http://imgur.com/a/iVIRF

 

And here all engines, that need electricity to run.

http://imgur.com/a/PWQvX

Edited by raxo2222

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It seems like we are getting max 217 newtons per megawatt -  for rocket launch nozzle and thermal ramjet.

Isn't that bit low?

Numbers are for Hydrogen if applicable.

 

Edited by raxo2222

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9 hours ago, Nansuchao said:

@FreeThinker, a great news, it's official, the EM drive works: http://arc.aiaa.org/doi/10.2514/1.B36120

Now we just have to wait until a space company dares to put it to the ultimate test by putting it in orbit with a decently sized solar array and fly away! It would start a new era in space exploration!

Edited by FreeThinker

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9 minutes ago, FreeThinker said:

Now we just have to wait until a space company dares to put it to the ultimate test but putting it in orbit with a decently sized solar array and fly away! It would start a new era in space exploration!

Hopefully soon, but realistically I don't expect to see it in action for another decade more or less. Future missions are already planned and I don't think they'll use such propulsion, for now. The good news it's that it works, it's no more a theory with few proofs.

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35 minutes ago, raxo2222 said:

It seems like we are getting max 217 newtons per megawatt -  for rocket launch nozzle and thermal ramjet.

Isn't that bit low?

Numbers are for Hydrogen if applicable.

 

let's calculate assuming isp 1000s:

trust = power /  (exhaust velocity * 0.5) =  1 MJ / (1000 * 9.81 * 0.5) =   1000000 Joule / (9810 m/s * 0.5) = 204 newton

It seems to be right!

3 minutes ago, Nansuchao said:

Hopefully soon, but realistically I don't expect to see it in action for another decade more or less. Future missions are already planned and I don't think they'll use such propulsion, for now. The good news it's that it works, it's no more a theory with few proofs.

It still not a proof, they only made a better test setup trying to disprove it, which failed. Until it will actually fly in space, the skeptics will always object

Edited by FreeThinker

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15 minutes ago, FreeThinker said:

let's calculate assuming isp 1000:

trust = power /  (exhaust velocity * 0.5) =  1 MJ / 1000s * 0.5 =   1000000 Joule / (9810 m/s * 0.5) = 204

It seems to be right!

I tested various propellants for rocket launch nozzle, and liquid Nitrogen generates most thrust.

I'm getting 0.697 kN/MW. ISP is 318.4, like its chemical rocket.

It is even better than Hydrogen/LiquidFuel/Methane + Oxidizier combination.

It seems like liquid nitrogen and rocket nozzle is best for heavy lifting.

I used 10m thermal only energy fusion reactor on D-T mode and that thermal engine.

Lets see 5m antimatter reactor and thermal ramjet with Nitrogen. 0.281 kN/MW.

I guess this is tied to ISP - its 803 in this case.

So if I tried coldest reactor I would get 0.700 or even 0.800 kN/MW.

Edited by raxo2222

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Hello everyone !

While testing one of my beautifulest plane to date (never actually succeded to make one that flies), I encountered a limitation regarding the Molten Salt Reactor / Thermal turbojet combo : the temperature of the later doesn't stabilize during flight, it goes up and eventually reaches 2750K and explodes. Of course I have KSPI radiators for thermal waste, air intakes. I also tried the engine pre cooler, the stock radial radiator, the big-ass KSPI folding radiator, and it still overheat, eventually. 

I posted in the " KSP interstellar for dummies", in case i was doing something wrong, but they were unable to give me further options, besides coming here. I reproduced the problem with a stock install with only KSPI installed (the latest version), and it still does it. Something I noticed is that when manually limiting the thermal turbojet thrust, it accelerate the rate at which the temperature rises in the engine.

Could it be a bug in the temperature/thermal system ? Then again, it is highly possible that i missed something and am doing something wrong.

 

Here are both the output.log of my latest test and the craft file used for that same test : 

https://www.dropbox.com/s/lk960z3wcugqwr3/output_log.txt?dl=0

https://www.dropbox.com/s/0uyh23h0yae5i3x/Glowing Creçerel I.craft?dl=0

 

 

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Here are the pics. In the SPH screenshot i removed the KSPI radial radiators in order to have visibily of both the reactor and the thermal turbojet.

reactor and thermal turbojet are 1,25m diameter, the fuselage is all stock parts.

LvsDmbXm.png
cDPeeKbm.png
zIRwFb2m.png
Q8kZqJAm.png

Edited by MagpulMasada
switched to clickable screenshots

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If you are using atmospheric mode at high speed you also need to add a precooler. It also helps to active the thermal radiators which are off by default

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Already tried that, even with multiple precooler for a single engine on a static test right, and also on this design, by attaching the precooler right before the turbojet.

Thank you for helping BTW.

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43 minutes ago, MagpulMasada said:

Already tried that, even with multiple precooler for a single engine on a static test right, and also on this design, by attaching the precooler right before the turbojet.

Adding it right before the nozzle is not enough, what counts is the distance between the air intake and the precooling, which cannot be more than 1

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1 hour ago, FreeThinker said:

Adding it right before the nozzle is not enough, what counts is the distance between the air intake and the precooling, which cannot be more than 1

Just tried putting subsonic radial intake, temperature does stabilise on my single reactor design. but it's very sensitive to airflow changes, such as turning or going up and down. On my Bi-reactor design, it's very variable. Sometimes i would just shut some of my intakes and the temp would decrease madly, so i'd remove all the intake except one per precooler, but then on a new flight it would overheat again.

I suspect this has something to do with the flow rate of air.

 

EDIT : TBO even with my 1 reactor design it's rather variable.

Edited by MagpulMasada

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Oh weeeeell I guess you pinned what was wrong, i thought those were passive radiators. All those hours for that... :P

 

EDIT : It does work a lot better when i actually activate those radiators.

 

Thank you very much for taking the time to help me ! 

Edited by MagpulMasada

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