Foxster

Build a coal-powered aircraft

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Your task today, gentlemen and ladies, is to build an aircraft powered only by coal ore. 

Here's my first attempt. Didn't quite make it but it was close..

jS6nnpp.png?1

The rules:

  1. Stock + no cheats + manned
  2. No fuel to be made before leaving the ground
  3. Your aircraft must be capable of sustained level flight for at least 10 minutes
  4. You may start with no more than a ROUND-8's worth of LF+O (just to help you get off the ground)
  5. Once you reach cruising level, your 10 minutes start
  6. Once cruising, your liquid fuel level must not drop anymore (i.e. you need to be making the same or more LF than you are using)

Two challenge levels:

  • Engineer Assist: Have an engineer on board (fuel generation is more efficient, especially at 5*)
  • Unassisted: No engineer aboard. 

Good luck, chaps!

(Ore-only space plane?)

 

Edited by Foxster

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Seems interesting! I'll try building something as soon as I get home.

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*Note* I am an automation addict.  I shamelessly used Atmosphere Autopilot.
*Note2* I found a cheat (stock!) that made this excessively easy.


Got one:  
FRyHaQw.png

Finally got to a cruise:  This was fuel state before setting off the ISRU

8L64SmA.png

e0xSy4c.png

 

This is my cheat:

rTfe08F.png

(An Engineer has some large bonus to running the ISRU I couldn't get it to stay in the air with a pilot - but with an engineer I was never hurting for fuel and was actually worried about running out of ORE!)

 

Note the time and fuel state:

v1HR1J1.png

Still in the process of flying back home...

Tons of fun!  Thanks for the challenge!

(it would be better if you banned engineers - or made it required that there be at least 1 pilot onboard)

Edited by daniel911t
Admit to my weakness

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Yeah, having the L5 engineer is a huge boon. I made one similar to Foxster's with 2 Junos that had 15 minutes of powered flight on 300 ore.

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Yeah... I just landed - 31 minutes and there was still some fuel left.
sgyvyZS.png


TzakDf2.png

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Yup. I found the huge bonus with an engineer rather than a pilot with my #2 craft. Taught me something, so that's good. Not a "cheat" for the challenge though, as it was a deliberately fairly easy challenge - just a bit o' fun. 

Be interested if this can be extended to larger craft or even an SSTO. Elcano? 

Edited by Foxster

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9 hours ago, Foxster said:

e interested if this can be extended to larger craft or even an SSTO.

We would have to solve the afterburner problem with this, since an afterburner uses something like three times the normal fuel. Maybe modify the challenge to allow for empty fuel and oxidizer tanks?

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23 hours ago, Foxster said:

ROUND-8's worth of LF+O

Didn't say it had to be an actual ROUND-8. 

Though we'd best say you have to make the fuel whilst airborne, otherwise we could just make a load of fuel before lift-off, dump the ore-tanks and ISRU and do a normal lift. 

I'm going to try to make an orbiter. Most likely won't be an SSTO but so what. 

Edited by Foxster

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Just now, nascarlaser1 said:

what is/how to tell when you reach "Cruising level"?

Don't want to be overly prescription here but I'd say once you get to level flight, wherever that is efficient or comfortable for you. 

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31 minutes ago, Foxster said:

Don't want to be overly prescription here but I'd say once you get to level flight, wherever that is efficient or comfortable for you. 

so not gaining/losing altitude?

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4 minutes ago, nascarlaser1 said:

so not gaining/losing altitude?

It doesn't matter if you wobble about a bit, it's hard not to without an auto-pilot. The idea was that's it's the altitude you are going to fly at for 10 minutes after the climb following lift-off. 

Edited by Foxster

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Hey guys.

 

Tanks thanks for the challenge. T'was fun.

From engine start to survivable crash 42 minutes.

Album (From the bottom up) http://imgur.com/a/LgKIu

I could have done slightly better as I forgot do drain the mono-propellant and the oxidizer.

Engine start

Tkd9XBRg.png

Dumped the gears

juQuXrrg.png

Ore just ran out at 25:11

fj7bUWsg.png

I can see Florida

ZfCYFFcg.png

Fuel no more at 39:11

UUIhnBjg.png

The controlled crash was at 42:10

wrLX7qug.png

6t2uR1Mg.png

 

ME

Edited by Martian Emigrant

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Nice job, ME.

One little thought...You might find using a mk1 command pod rather than a lander can works better. The lander can is very draggy, even with a nosecone on it.

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44 minutes ago, Foxster said:

Nice job, ME.

One little thought...You might find using a mk1 command pod rather than a lander can works better. The lander can is very draggy, even with a nosecone on it.

True, very true.

 

But I went for weight first. The idea being that at lower speeds the drag is less.

(Not too sure here. I think the drag might directly proportional to speed in the game. But real-life it's the square of the speed)

The Weesley was also flat-rated at 33% to help keep the speed reasonable.

 

ME

 

EDIT

I just added a picture to the album.

FLPfBW8g.png

You can see the craft doesn't drag a lot.

Edited by Martian Emigrant

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Level 5 engineer make it quite easy... 

What about reworking the challenge a little? Just add a special difficulty "I ain't no engineer" ? :D

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Soooo, I've been trying to make up a plane that could stay up without the need for an engineer but no dice so far.

I've chosen the ultra-light path so I can keep in the air with minimal airspeed (around 60 m/s on this one). I can keep this baby up with a level 1 engineer or better.
Still, with a pilot I don't split even (yet).

 

Spoiler

The plane filling tank

GJjTetR.png<

Tank are full, let's take off

KujqmlV.png

Take Off

8p07dy3.png

Shot with the Sun above

BEqdjjT.png

Maneuvering to get in line with Old Airfield

jiAhu5Z.png<

Terribly sloppy approach

RZAaV1f.png

Well that didn't end well, did it?

PsBJJ3R.png

 

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3 hours ago, wibou7 said:

Level 5 engineer make it quite easy... 

What about reworking the challenge a little? Just add a special difficulty "I ain't no engineer" ? :D

Good idea. Will do. 

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Hmm, This seems like a good challenge I'll give a shot later. But that comparison of ore to coal hmm...

Ok, here was my attempt:

(Start)

I actually based this off a real coal powered aircraft design: https://en.wikipedia.org/wiki/Lippisch_P.13a

Oh and flown by an engineer.98e66636eaa8400b325a729f28abf038.png

86d630eccce070aec1a30959a04810fe.png

Like its not even draining "Steam!"

eea05c2a71cbdd01b56be7c5373d6a4b.png

c1c1dc650a3119c5c8b4a544edc613ce.png

Moment we run out of coal, though IRL steam locomotives are capable of running without coal for a short period of time, so theoretically shouldn't steam planes be able to run a short time without "coal?" It took like a min to get to cursing alt so maybe 15 min?

c11d7a84ea08b3476e330e51a5f281ca.png

(Total time)

Edited by Spacetraindriver

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2 hours ago, Spacetraindriver said:

Hmm, This seems like a good challenge I'll give a shot later. But that comparison of ore to coal hmm...

Ok, here was my attempt:

(Start)

I actually based this off a real coal powered aircraft design: https://en.wikipedia.org/wiki/Lippisch_P.13a

Oh and flown by an engineer.

 

Like its not even draining "Steam!"

 

 

Moment we run out of coal, though IRL steam locomotives are capable of running without coal for a short period of time, so theoretically shouldn't steam planes be able to run a short time without "coal?" It took like a min to get to cursing alt so maybe 15 min?

 

(Total time)

My initial plane looked a bit like yours and was flown by a pilot - the problem that became immediately obvious was that I needed excessive throttle (about 1/4) to maintain level flight.  That level of power was just the tiniest amount negative and the round 8 was draining at a rate of 0.01, sometimes.  I tried again with more wing area and was able to achieve cruising flight at about 2KM at a speed of 100m/s with a positive fuel production rate.  Wing area was more important than lightness, in my experience.

I understood the Liliquidch was essentially a normal ramjet engine that was fueled by coal powder.  If the fuel goes away, there's no more power.  The reason a locomotive continues to go after fuel is exhausted is the enormous amount of heat stored in the boiler, a jet of any type doesn't store any energy.  A steam locomotive will continue to have power available as long as the boiler is above 100C - and even as it decreases below that there may be some residual pressure. (Incidentally, this is the same on a nuclear powered ship!)  Any jet, (except for a thermal nuclear jet) will stop producing thrust as soon as fuel isn't being injected into the combustion chamber.  

In the '80s Chrysler even tested one of their turbine cars with a coal fuel source. http://jalopnik.com/gm-once-built-these-fascinating-coal-powered-turbine-ca-1791842557

I like your plane! :)

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I'm coal powered. Easy to stay warm, hard to get cold though.

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I decided to try again - this time with more wing and only a pilot.

TEx4qxf.png

fuselage is the same as my first attempt, but the wings and heatsinks were changed.

It took a while to start making enough fuel, and I had to actually plot a graph to find the absolute bottom of my power curve

60 m/s -13.6 kn thrust required

65 m/s - 13.3 kn

68 m/s - 13.2 kn

70 m/s - 12.8 kn

75 m/s - 12.6 kn

77 m/s - 12.3 kn

80 m/s - 12.6 kn

85 m/s - 12.7 kn

As soon as the numbers started climbing again I knew there was no point going any faster - form drag (drag created by the airframe) goes up with the square of the speed, so as soon as power required started to tick up, I knew I was getting away from max efficiency.  When going slow, induced drag is dominant (drag from making lift), as you speed up, less AOA is required to make the same lift, therefore less induced drag, until form drag comes up and takes over.  The magic spot where the curves for form drag and induced drag meet is the most efficient.  It's somewhat counter-intuitive, but if you go slower than that magic spot, it actually requires more power the slower you fly.  
For this airplane that magic point is just about 77m/s.

This thing flies forever.  I got over an hour of flight time out of just the round 8 and ore.

Jgdnu35.png

uZ8577O.png

Right before finally running out of fuel.
7tO4iYL.png

Super fun challenge!  I'm thinking multi engine next.  I have serious doubts about SSTO, I just don't think the power's there, unless you can use a larger holding LFO tank...

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Nice job.

I found the small radiator was enough to keep the working temp of the ISRU at 1000°. 

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15 minutes ago, Foxster said:

Nice job.

I found the small radiator was enough to keep the working temp of the ISRU at 1000°. 

If you look at my pics you'll see that the ISRU settled in at about 1100, even with the two large radiators.  I'm frustrated that their cooling ability doesn't seem to be impacted by airflow.  I would expect much, much greater cooling efficiency with fluid flow over the radiator and with a greater delta T.  (it should be much cooler at 5000M than at the surface)

Sadly, it doesn't seem that KSP works that way.  I didn't notice any difference in cooling performance under any circumstances.

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Dumb question - you are turning them on, right?

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