Stock Turboprop Endurance Record

[Gman_builder]

Stock Turboprop Endurance Record

 This challenge is based heavily on stock turboprop technology and if you do not know what that is but still want to try out the challenge I suggest looking at THIS thread first. But essentially a stock turboprop is a shaft with a prop on the end driven by exhaust gasses from jet engines. to make a turboprop that can really do anything of any notability you must increase the RPM limiter in your physics.cfg. There is a line called Max Angular Velocity that needs to be increased from 30 to 60 or higher. This is not cheating as your not changing any physics of the game. Only increasing the RPM limiter. It's like taking the governor off your car.

Here is some examples you can download and test.

Anyway, This will be a two part challenge, flight time and distance traveled. The goal is to design and built a highly efficient stock turboprop engine that can fly farther and long than everyone else's.

RULES

1. Your craft must be a stock turboprop of some nature, be it a helicopter or plane

2. Your aircraft must be completely stock. No exceptions.

3. You can use any variety of plugins such as Pilot Assistant, MJ, or the like as long as it doesn't change the game physics are add any non stock parts onto your craft. MechJeb parts are allowed because of the nature of the mod.

4. No cheats at all. However, to make a successful turboprop you have to set the global drag multiplier slider to 0 in the

Alt+F12<Physics<Aero tab.

5. If you can somehow stage a Air-to-air refueling I shall allow it.

6. You must actually do the entire flight, not just read off the estimated flight time provided by some mods.

7. You must provide screenshots documenting the flight.

 

WINNERS

Longest Distance Traveled

1.

2.

3.

Longest Time Spent in the Air

1.

2.

3.

 

 

Work has begun on my entry....Fear me...

 

Azimech if there's anything I might have left out please tell me.

Edited July 12, 2016 by Gman_builder

[The Optimist]

DAMNIT THERE GOES THE REST OF MY WEEK

Edit: I suspect that the winners of this exercise will go to the reaction-wheel propellers due to the very nature of their propulsion system.

Edited July 5, 2016 by The Optimist

[Jakalth]

That may be true if it wasn't for the fact that this is a Turboprop challenge, which means jet engine blowers.  Although that might need to be specified in the rules, or have a separate class for the electric types?

[Gman_builder]

57 minutes ago, The Optimist said:

DAMNIT THERE GOES THE REST OF MY WEEK

Edit: I suspect that the winners of this exercise will go to the reaction-wheel propellers due to the very nature of their propulsion system.

That's not a turboprop engine. I was thinking about that as well and determined that if you used electric engines like that, 1. They aren't really considered turboprops, and 2. They could fly in a aircraft similar to Solar Impulse 2 and essentially run forever.

36 minutes ago, Jakalth said:

That may be true if it wasn't for the fact that this is a Turboprop challenge, which means jet engine blowers.  Although that might need to be specified in the rules, or have a separate class for the electric types?

Having a spate class is pointless because, since they are electric, they can essentially run forever on solar power.

[The Optimist]

2 minutes ago, Gman_builder said:

That's not a turboprop engine. I was thinking about that as well and determined that if you used electric engines like that, 1. They aren't really considered turboprops, and 2. They could fly in a aircraft similar to Solar Impulse 2 and essentially run forever.

so, the challenge becomes who can build the plane with the most fuel tanks

[Jakalth]

6 minutes ago, The Optimist said:

so, the challenge becomes who can build the plane with the most fuel tanks

fair enough.  But the challange is still building a turboprop that can actually move an aircraft with a lot of fuel on board.  If someone can pull that off though.  It would be impressive.

 

I intend to give this a try.  Hopefully, if I can find the time for it now that my vacation is over...

Edited July 6, 2016 by Jakalth

[Gman_builder]

5 minutes ago, The Optimist said:

so, the challenge becomes who can build the plane with the most fuel tanks

No, you have to design a engine that can actually lift those fuel tanks and do so reliably and quickly. This one is many magnitudes more challenging than my other endurance challenge.       Have fun....

[Azimech]

Drop tanks yes/no?

Also, mentioning the max angular velocity modifier is a good thing, it really makes the engines much more efficient.

And I'd request pictures of take off, climb, every 15 minutes of level flight, just before tanks running dry and another just after engine cut-off; with the resource window open. Also you didn't mention engine cut-off or (touchdown/crash/splash), if you allow the glide down to be added to total time/distance covered.

V.O.I.D. shows distance to KSC, that really helps a lot.

Edited July 6, 2016 by Azimech

[Azimech]

My first attempt, without drop tanks. This is my prototype twin-turboprop cargo plane using the Chakora engines, a total of 144 blowers! I was able to take off with engines at ~50%, starting mass 150 tons. This means there's room for improvement. Decided to keep the engines within safety limits so never exceeded 39 rad/s and 75% throttle, climb & cruise speed low at ~110 m/s.

Either there's a bug in 1.1.3 or something else is going on, I wasn't able to transfer fuel from the nose tank and therefore I ended up with a nose heavy plane and 1125 units of unburned fuel when the engines shut off.

So I started the glide down and feathered the props as much as possible but after a few minutes disaster struck. The Chakora engine was never designed for opposite thrust. A heavy jolt in engine 2 destroyed some bearing elements and resulted in the front tank + cockpit breaking loose.

Distance flown until tanks empty: 265.6 km.
Flight time: 42:03.
 

 

[Gman_builder]

6 hours ago, Azimech said:

Drop tanks yes/no?

Also, mentioning the max angular velocity modifier is a good thing, it really makes the engines much more efficient.

And I'd request pictures of take off, climb, every 15 minutes of level flight, just before tanks running dry and another just after engine cut-off; with the resource window open. Also you didn't mention engine cut-off or (touchdown/crash/splash), if you allow the glide down to be added to total time/distance covered.

V.O.I.D. shows distance to KSC, that really helps a lot.

I didn't exactly say drop tanks WERN'T allowed. So ya you can have them. I put links to the forum thread and kerbalX hangar which both have much more information about the RPM cap and other stuff than I could ever or really want to put here. If you can build turboprops i'm assuming you already have VOID lol. I guess this is a challenge for the advanced KSP engineer. NICE ATTEMPT! I am taking a MUCH different approach...

Edited July 6, 2016 by Gman_builder

[Azimech]

On 6-7-2016 at 8:54 PM, Gman_builder said:

I didn't exactly say drop tanks WERN'T allowed. So ya you can have them. I put links to the forum thread and kerbalX hangar which both have much more information about the RPM cap and other stuff than I could ever or really want to put here. If you can build turboprops i'm assuming you already have VOID lol. I guess this is a challenge for the advanced KSP engineer. NICE ATTEMPT! I am taking a MUCH different approach...

Got an attempt yet?

[Gman_builder]

19 minutes ago, Azimech said:

Got an attempt yet?

I'm working on a engine. It has 150 parts and 2 meters in diameter. It is also a pusher prop configuration to eliminate the thrust bearing which seems to be the buggiest part of all engines.

[quasarrgames]

I could automatically win... If i had the time and patience to keep this thing in the air for long enough.

It's an electric turbine plane powered by 2 rtgs. With correct trim and micromanagement, it can have 0.00 electricity drain, making it run virtually forever.

I'm too lazy to do that though, and i'd guess this challenge is supposed to use jet engines only. I just kind of wanted to show off. sorry

[Azimech]

Electric motors are like ... flying vacuum cleaners. Oh wait ... jet engines are like flying vacuum cleaners. Electric motors are more like electric ceiling fans. Efficient but boooring!

[The Optimist]

5 minutes ago, Azimech said:

Electric motors are like ... flying vacuum cleaners. Oh wait ... jet engines are like flying vacuum cleaners. Electric motors are more like electric ceiling fans. Efficient but boooring!

Perpetually powered but... Boring!

[sdj64]

Bigger might not be better for turboprop efficiency.  Here is an entry with a small plane that has 63 parts in the whole plane, including 36 in the prop!  Only 2 blowers, but much more powerful than my old biplane because they are pushing at a larger radius, making more torque.  This plane is slower than the 8-blower one I made for the speed challenge, topping out around 80 m/s in level flight with minimum drag in the settings.

 

Flight time 1:19:30

Distance 378.2 km

Distance was calcuated using the latitude and longitude because targeting the rover back at KSC didn't show the icon for some reason.

[Azimech]

Great entry, @sdj64!

Here's my second attempt with my heavy cargo plane, corrected the problem of the nose tank not being used and added drop tanks in the cargo bay. Fuel logistics are a nightmare in 1.1.x. It's still using my Chakora v1 engines instead of the improved ones, which run at a much higher RPM and thus more efficient but harder to operate. I damaged the engines during take-off due to demanding too much power but they kept running anyway, after that I kept throttle at 66% the rest of the flight.

Flight time 1:12:08.
Distance 430 km.
Splashdown distance: 449.94 km.

I might try a single engine next time. Better aerodynamics & part count.

 

[Gman_builder]

50 minutes ago, quasarrgames said:

I could automatically win... If i had the time and patience to keep this thing in the air for long enough.

It's an electric turbine plane powered by 2 rtgs. With correct trim and micromanagement, it can have 0.00 electricity drain, making it run virtually forever.

I'm too lazy to do that though, and i'd guess this challenge is supposed to use jet engines only. I just kind of wanted to show off. sorry

Ya basically all reaction wheel planes can run forever. So honestly that isn't really any different  And yes this challenge is for jet engine powered turboprop planes only.

[The Optimist]

I'm having trouble with the bearings. The internal rod keeps slamming into the wheels, and even at minimal suspension it bends the wheel cage. This causes loss of rotational energy, and it makes the bearing ridiculously unstable.

[Gman_builder]

11 hours ago, The Optimist said:

I'm having trouble with the bearings. The internal rod keeps slamming into the wheels, and even at minimal suspension it bends the wheel cage. This causes loss of rotational energy, and it makes the bearing ridiculously unstable.

If there is high vibration, first try using different wheels. If that doesn't fix it try offsetting the wheels different distances from your driveshaft. Also, the perfect spring - damper ratio Is essential to a stable bearing. I'll post some pics and specs of the engine I will put in my new plane when I have worked out the kinks. But so far it has a top speed of around 80/s on a cart and a max RPM of 27 RAD/s. It's not that much but I am only using 6 Junos so.

[DoctorDavinci]

So this is what I have been working on ... 172 parts IIRC

Got 6 panthers running it but imma thinking I may go to a bunch of Juno's instead although that will put the part count through the roof

 

[Cunjo Carl]

24 minutes ago, DoctorDavinci said:

Got 6 panthers running it but imma thinking I may go to a bunch of Juno's instead although that will put the part count through the roof

That engine is beautiful. Just. WOW.

Watch out for the terrible ISP on those Junos. Their tiny size and extremely gentle air usesage is enticing, but that ISP will probably be a huge problem for any endurance challenge. Of course I'm using them anyway in the other endurance challenge because they're so cute, but hey that's me.

I think I'm gonna go watch your engine test video again....

[Gman_builder]

1 hour ago, DoctorDavinci said:

So this is what I have been working on ... 172 parts IIRC

Got 6 panthers running it but imma thinking I may go to a bunch of Juno's instead although that will put the part count through the roof

 

The video Is too low res to see any small numbers but I think I was able to make out 40 RAD/s. It that right?

[DoctorDavinci]

I think I was getting 12 RAD/s with full throttle and 15 with afterburners .. The P-6 goes boom without the propellors due the lack of air resistance with them removed

I found that the key to building a working turbine in KSP is following the same basic principles you would use when building an actual turbine IRL ... You must find balance, meaning balance your impeller shaft before building the cage ... if the shaft ain't balanced it'll get all floppy

 

 

[Azimech]

For achieving high efficiency & speed, the RPM really needs to go up, guys.