[Stock Helicopters & Turboprops] Non DLC Will Always Be More Fun!

[The Optimist]

Editor Extensions Redux is no longer working for 1.1.2 for some reason.

[Pds314]

Twin Engine bomber and light fighter:

Assymetric Engine testing with brakes at 200%:

Flight!

A particularly bad engine failure: 

Light fighter, currently running on infinite fuel: 

10000 HP and 165000 Foot-lbs of torque in a conveniently small package. Comes complete with air intakes, fuel lines, prop and probe core with RTG.

Edited July 13, 2016 by Pds314

[Pds314]

So it's interesting to note the aircraft power/weight ratios.

My medium fighter has a weight of 7.7 tonnes fueled, with 2000 kW = 260 W/kg.

My small fighter has a weight of about 4.3 tonnes empty, with about 1400 kW = 330 W/kg. (49 Rad/s engine really helps, though it'll be less when I add fuel tanks)

My twin engine bomber has a weight of about 63 tonnes fueled, with about 15500 kW = 246 W/kg.

I wonder if it makes sense to use power/weight is a sort of figure of merit for these aircraft and their respective engines.

Edited July 13, 2016 by Pds314

[Gman_builder]

@pds2363Can you post both your small and large engines? I'd love to take a closer look at them.

[Pds314]

19 minutes ago, Gman_builder said:

@pds2363Can you post both your small and large engines? I'd love to take a closer look at them.

Yes. I shall post them in about an hour. I don't have an electric socket at the moment and my laptop lasts an unuseful amount of time on battery. For convenience sake, I shall post both the clockwise and anticlockwise versions of Propler E-18L3. They generate + or - about 0.5% of the same torque. BTW, if anyone knows a way to mirror engines automatically, and not just put two same- direction engines on the same craft and try to perfectly mirror the components by hand, that would be greatly appreciated.

On a related note, it would be nice to have a compilation page of all things turboshaft. In particular, would be a detailed list of engines and aircraft with download links, as well as tutorials on construction techniques.

Edited July 13, 2016 by Pds314

[Gman_builder]

1 hour ago, Pds314 said:

Yes. I shall post them in about an hour. I don't have an electric socket at the moment and my laptop lasts an unuseful amount of time on battery. For convenience sake, I shall post both the clockwise and anticlockwise versions of Propler E-18L3. They generate + or - about 0.5% of the same torque. BTW, if anyone knows a way to mirror engines automatically, and not just put two same- direction engines on the same craft and try to perfectly mirror the components by hand, that would be greatly appreciated.

On a related note, it would be nice to have a compilation page of all things turboshaft. In particular, would be a detailed list of engines and aircraft with download links, as well as tutorials on construction techniques.

Theres a hangar on kerbalX that has all turboprops that work and have been posted on that website.

[Pds314]

Anticlockwise 18-blower prop engine: https://drive.google.com/open?id=0Bx5IDYRs0obMVGl0bXVkMk8yM2s

Clockwise version: https://drive.google.com/open?id=0Bx5IDYRs0obMUW93c0VrQmhIODA

Tiny Clockwise 4-Juno engine: https://drive.google.com/open?id=0Bx5IDYRs0obMeDJneGFkMnVkS1E

2-engine bomber: https://drive.google.com/open?id=0Bx5IDYRs0obMbHRjS3pPaThJNHM
 

[Pds314]

Hmm... it appears that the reason for not being able to reach appropriate speeds for the engine power level is not principally prop design, but expansion at high speed. This means we should optimize for props which minimize expansion, possible via aerodynamic forces.

[Pds314]

Between significantly improved engines and having more of them, I managed to push my bomber to 140 m/s while climbing. It ought to be capable of much higher speeds, but I have to go.

Another convenient thing is that these engines can allow up to 47 Rads/sec before they blow up, at least, they can on the 2-engine bomber. Somehow I messed with the props on the experimental version enough to cause problems at 41 or so.

Edited July 13, 2016 by Pds314

[Pds314]

I think the next thing I'll make is a single- engine plane using the modified E-18L3. Alternatively, I may design a mk3 engine to compete with Azimech's Chakora, since that seems to be the current state of the art for engines around that size. (unless Azimech has a super secret engine with absurd capabilities.)

Edited July 13, 2016 by Pds314

[Gman_builder]

3 hours ago, Pds314 said:

I think the next thing I'll make is a single- engine plane using the modified E-18L3. Alternatively, I may design a mk3 engine to compete with Azimech's Chakora, since that seems to be the current state of the art for engines around that size. (unless Azimech has a super secret engine with absurd capabilities.)

Ya Azimech's black project engines. Developed in Area Az by classified team of Squad devs and veteran players.

[Pds314]

38 minutes ago, Gman_builder said:

Ya Azimech's black project engines. Developed in Area Az by classified team of Squad devs and veteran players.

The engine I'm designing shakes like a crazy thing. It's not that it isn't turning the prop, just that the wobble is insane.

EDIT: oh, um.. hmm... The shaft had snapped in two. That could explain it...

It currently seems as thought it is not limited by RPM but rather prop thrust, as at max prop pitch, the speed is a stable 41.5-41.7 rad/s, whilst if I lower prop pitch, the speed is reduced to about 36-37 rad/s due to prop thrust generation, but it explodes violently.

Edited July 13, 2016 by Pds314

[Gman_builder]

47 minutes ago, Pds314 said:

The engine I'm designing shakes like a crazy thing. It's not that it isn't turning the prop, just that the wobble is insane.

EDIT: oh, um.. hmm... The shaft had snapped in two. That could explain it...

It currently seems as thought it is not limited by RPM but rather prop thrust, as at max prop pitch, the speed is a stable 41.5-41.7 rad/s, whilst if I lower prop pitch, the speed is reduced to about 36-37 rad/s due to prop thrust generation, but it explodes violently.

well I guess you better make a better engine then!

[Pds314]

3 minutes ago, Gman_builder said:

well I guess you better make a better engine then!

Currently tweaking it. The main issue is that you have many hundreds of kiloNewtons, if not MegaNewtons, pulling on an avionics nosecone. The tensile strength of the shaft can be supplemented with better load distribution and struts, but only to a point. I think the next engine I build will probably not have avionics cones directly connected to avionics cones. They're simply not up to it.

[Pds314]

Wow....

Apparently, it's possible to pull the shaft straight out of the engine fully intact:

[Pds314]

49.7 rad/s at nearly half the speed of sound! 220 kN net thrust! (it can go get much more thrust at low speeds. Probably in excess of 500 kN, but too much higher will blow the prop up)

Hmm.. It looks like it can do 600 kN net thrust, but it very quickly exceeds its max spin rate.

Edited July 13, 2016 by Pds314

[Pds314]

710 kN of thrust @ 39.7 rad/s.

Unfortunately, I don't think it can go much higher. It blew up two seconds later and definitely hadn't over-revved. Still, over 1 tonne per blower of thrust is not bad.

Alright. I think I'm gonna just spec it as do-not-exceed 650 kN. Every test where it even briefly reaches 700 ends in disaster.

Edited July 13, 2016 by Pds314

[The Optimist]

I want to make something to compete, but since Editor Extensions crashes my game every 10 minutes, I can't. Anyone have a way to remove the offset limits without that mod?

[Pds314]

29 minutes ago, The Optimist said:

I want to make something to compete, but since Editor Extensions crashes my game every 10 minutes, I can't. Anyone have a way to remove the offset limits without that mod?

You're making something bigger than the SPH?

[Pds314]

My creation! It is alive! Well, at least if you make it invulnerable during physics load. Thrust in-flight is competitive with jet airliners of comparable wingspan!



Specs:

Wingspan: 52.3 meters.

Length: 48.0 meters.

Empty weight: 104 tonnes.

Fueled weight (as flown): 303 tonnes.

Max Takeoff weight: A lot. Really, A LOT.

Maximum thrust: 1400 kN without exploding. 1200 kN safely. Yes, taking a light fuel load could potentially allow vertical climbs.

Engines: 2x Varpulis 72-blower 3-meter turboshaft.

Engine specs:
    Recommended RPM limit: 48 rads/s.
    Failure RPM: 50.5 rad/s.
    Blowers: 72x Juno
    Recommended thrust limit: 600 kN.
    Failure thrust: 700 kN.
    Mass, including propeller and radially mounted intakes: 25.3 tonnes.
    Torque radius: 1.25 meters.
    Blower thrust: 20 kN * 72 =1.44 Mn (always less in practice).
    Calculated torque: 1.8 Mn*m
    Nominal Power at 48 rads/s: 86 MW = 115000 HP

Edited July 14, 2016 by Pds314

[Jon144]

1 hour ago, The Optimist said:

I want to make something to compete, but since Editor Extensions crashes my game every 10 minutes, I can't. Anyone have a way to remove the offset limits without that mod?

Yes. You need to open your settings file within your KSP directory. Go into the file and fine the VAB_FINE_OFFSET_THRESHOLD line. Increase this to some outlandishly huge number can you can offset a part anywhere you want as long as you are pressing down the shift key. Simple.

[Pds314]

DOWNLOADS:
Varpulis engine (Clockwise)

Varpulis engine (anticlockwise)

Jumboliner A2 (big plane, 701 parts, REMEMBER TO MAKE INVULNERABLE DURING PHYSICS LOAD!)
 

Edited July 14, 2016 by Pds314

[Gman_builder]

7 minutes ago, Pds314 said:

DOWNLOADS:
Varpulis engine (Clockwise)

Varpulis engine (anticlockwise)

Jumboliner A2 (big plane, 701 parts)

You just innovated more in the past few days than the entire community has in years.

[Pds314]

1 minute ago, Gman_builder said:

You just innovated more in the past few days than the entire community has in years.

The only really helpful things about that engine are:

#1. Wheelless.

#2. Blades hardly expand.

Other than that, it's pretty much an upscale of the technology from my previous wheelless engines.

[Gman_builder]

Just now, Pds314 said:

The only really helpful things about that engine are:

#1. Wheelless.

#2. Blades hardly expand.

Other than that, it's pretty much an upscale of the technology from my previous wheelless engines.

I mean everything you've done. previously the best performing wheelless engines could barely lift the lightest airframe possible.