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

[Gman_builder]

11 hours ago, Azimech said:

Don't know how it is on other machines but on mine physics go gaga above 50 rad/s.

Anyway, there's more to come, just improved the Chakora engine to run at least 46 rad/s! How I've done that ... that will be my little secret for now

I see how it is.......

[selfish_meme]

So I built this little test rig, runs nice, does not get airborne despite several absolutely brilliant ideas  Download it and play with it all you like, I won't have much time in the near future to do much of anything. Drag is stock, gets up to about 20ms

Whole Craft

https://drive.google.com/open?id=0B8-nkDP75eETTWdySDNVMGhLTE0

Turboprop

https://drive.google.com/open?id=0B8-nkDP75eETbzhYS0lmdkk2bmM

 

[Gman_builder]

@selfish_meme If you ever re visit turboprops, I suggest making them much larger. Like, MK3 cargo bay size.

[selfish_meme]

54 minutes ago, Gman_builder said:

@selfish_meme If you ever re visit turboprops, I suggest making them much larger. Like, MK3 cargo bay size.

Ive made them before, was trying to miniturize

[Gman_builder]

3 hours ago, selfish_meme said:

Ive made them before, was trying to miniturize

Gotchya

[Azimech]

Yo Gman_builder, shall we post our speed records in the challenge topic? Would be a cool post how you beat my record 3 times.

Cool what you did with the Gremlin MK2: 224, excellent!

I'll wait for your post there ... then I'll post my reply ... because I have news for ya ...

 

[Azimech]

9 hours ago, selfish_meme said:

So I built this little test rig, runs nice, does not get airborne despite several absolutely brilliant ideas  Download it and play with it all you like, I won't have much time in the near future to do much of anything. Drag is stock, gets up to about 20ms

Whole Craft

https://drive.google.com/open?id=0B8-nkDP75eETTWdySDNVMGhLTE0

Turboprop

https://drive.google.com/open?id=0B8-nkDP75eETbzhYS0lmdkk2bmM

 

Too bad it didn't work out for ya ... hope you continue in the future!

[borbalf]

I have a new plane, this time it can reach 118m/s!

in the album you can see the DoubleHeart Mk IV (the first prototype to fly at over 100 m/s) and then the DoubleHeart Mk VI, my fastest turboprop so far!

I decided to place the double engine in the center of the plane, so that it would generate less torque. The engine is made of two bearings, one rotating clockwise and the other counter-clockwise, each with 4 blowers (J-404s "Panther" in wet mode) and 6 vanes at 50° (static). The main differences between Mk IV and MK VI are one less pair of wings and the structure above the plane to redice wobble

It takes off pretty easily at about 50m/s, but I suggest waiting until it reaches 65m/s to gently pull up; then it started slowly rolling clockwise, but nothing that couldn't be easily compensated with SAS

 

Craft file:

https://kerbalx.com/borbalf/LAC-DoubleHeart-Mk-VI

Now I have to make the prop pitch adjustable and maybe solve the bearing failure (always the landing gear overstressing, any ideas?)

[Azimech]

1 hour ago, borbalf said:

I have a new plane, this time it can reach 118m/s!

in the album you can see the DoubleHeart Mk IV (the first prototype to fly at over 100 m/s) and then the DoubleHeart Mk VI, my fastest turboprop so far!

I decided to place the double engine in the center of the plane, so that it would generate less torque. The engine is made of two bearings, one rotating clockwise and the other counter-clockwise, each with 4 blowers (J-404s "Panther" in wet mode) and 6 vanes at 50° (static). The main differences between Mk IV and MK VI are one less pair of wings and the structure above the plane to redice wobble

It takes off pretty easily at about 50m/s, but I suggest waiting until it reaches 65m/s to gently pull up; then it started slowly rolling clockwise, but nothing that couldn't be easily compensated with SAS

 

Craft file:

https://kerbalx.com/borbalf/LAC-DoubleHeart-Mk-VI

Now I have to make the prop pitch adjustable and maybe solve the bearing failure (always the landing gear overstressing, any ideas?)

Wow! Very cool design! I have a plane with engines front & back but never finished my design of a central mounted engine or engines.

[Gman_builder]

Alright, I posted the Gremlin MK2 in your challenge topic. After closer examination it appears that only @Azimech, @sdj64, @borbalfand myself  are the only people, to my knowledge, who have achieved at least 100m/s

@borbalfIf your bearing fails predictably, I.E. between a certain range of speed, your probably over speeding it. So you have to increase prop pitch to keep it from spinning to fast.

6 hours ago, Azimech said:

Yo Gman_builder, shall we post our speed records in the challenge topic? Would be a cool post how you beat my record 3 times.

Cool what you did with the Gremlin MK2: 224, excellent!

I'll wait for your post there ... then I'll post my reply ... because I have news for ya ...

 

Oh noooooooo

[Azimech]

Posting it here as well,  new speed record: 232 m/s (835 km/h)!

 

[The Optimist]

I'm planning out a design for a 4800 kN turboprop using the Tubettm dry fairing bearing. Prepare your angus beef sliders.

[Gman_builder]

3 minutes ago, The Optimist said:

I'm planning out a design for a 4800 kN turboprop using the Tubettm dry fairing bearing. Prepare your angus beef sliders.

That sounds incredibly powerful compared to current engines. I'm skeptical....

[Redshift OTF]

On 06/06/2016 at 0:33 AM, EpicSpaceTroll139 said:

Here's the Titan Mk1(-2)

Also, welcome to the forums @Koro

I've only just tried this but I am amazed! I've built a Chinook before but it never had the lift yours does plus it is smooth and stable to fly. I also didn't realise you could turn 1 object, (large fairing disk), with 2 engines. I'm guessing the SAS on the rotors keeps them stable?

I don't like the way the game caps RPM so I think I will try a different approach and go back to building better turbines. I'll stick to the stock aero-dynamics to start with.

The turbines are pretty compact for the amount of lift you get. They also lift almost 34 tons. 8 Juno's should only be able to lift 14 tons in a vtol configuration so I am creating more than twice the thrust with this setup. Something must be funny with the stock aero.

I'll try and do a video tomorrow with a craft if anyone wants it. I should add that Mechjeb states that this setup has a flight time of 2 hours and 3 minutes.

The downsides are that it's only good for up and down for now as roll and pitch create strange aerodynamic drag that causes the thing to oscillate wildly until its destruction. The thermohinges can't take side strain to well. I might have to look at some of Azimechs bearings since they seem to go so fast!

Edited June 16, 2016 by Redshift OTF

[Gman_builder]

@Redshift OTF So it is 250% efficient? Nice design!

Edited June 16, 2016 by Gman_builder

[EpicSpaceTroll139]

 

56 minutes ago, Redshift OTF said:

...am creating more than twice the thrust with this setup. Something must be funny with the stock aero.

Actually the SAS are just there to help stop them after landing, after which you can quicksave/quickload to reattach them to the main body via the docking ports. Idk what it would do with the rotor SASs on in flight, but I'm guessing it wouldn't be pretty.

As for getting more thrust with the rotors than you could from the jets alone, this doesn't indicate anything whacky (well, the way the jet exhaust efficiently spins the disk is weird, but continuing on). The rotors work based on real life principles.

So I'll give an explanation using 3 engine types.

So first off you have your turbojet.

It works by making a little bit of air move really fast out the back. This is good if you want to make a plane move fast at high altitude, but it has bad fuel efficiency when you're at low speed and altitude. The Concorde used this kind of engine.

Next you have your high bypass turbofan.

It works by making a fair bit of air move reasonably fast out the back. This is good for moderately fast speeds at fairly good altitude, and is pretty efficient. It is what you find in modern jetliners.

Then you have your turboprop.

It works by pulling a lot of air through a propeller relatively slowly, spinning it using a jet engine. This is good for low speeds and is quite efficient. It's used on short range commuter airplanes.

Basically, by looking at this trend, you get that by moving more air at a slower rate, you can get more force from a the same amount of fuel. However, you can't go as fast.

Helicopters use turbo shafts, which are basically oversized turboprops.

Edited June 16, 2016 by EpicSpaceTroll139
extended explanation

[selfish_meme]

22 minutes ago, EpicSpaceTroll139 said:

 

Actually the SAS are just there to help stop them after landing, after which you can quicksave/quickload to reattach them to the main body via the docking ports. Idk what it would do with the rotor SASs on in flight, but I'm guessing it wouldn't be pretty.

As for getting more thrust with the rotors than you could from the jets alone, this doesn't indicate anything whacky (well, the way the jet exhaust efficiently spins the disk is weird, but continuing on). The rotors work based on real life principles, just a few mins I'll explain 

Yes, helicopters and planes have much smaller engines than vtol craft necause it is much easier to push laterally to gravity and use aerodynamic surfaces for lift than use thrust alone to lift against gravity.

Edited June 16, 2016 by selfish_meme

[The Optimist]

21 hours ago, Gman_builder said:

That sounds incredibly powerful compared to current engines. I'm skeptical....

30 panthers

I wonder if a gear system would work. It probably wouldn't be very efficient if it did, due to KSP's *slightly* wonky physics engine, but it might let you make a larger gear turn the actual propeller much faster.

[EpicSpaceTroll139]

22 hours ago, The Optimist said:

I'm planning out a design for a 4800 kN turboprop using the Tubettm dry fairing bearing. Prepare your angus beef sliders.

And I thought the 1200kN rotor I was working on for a helicarrier was big...

[selfish_meme]

This is not beating any speed records yet, I used @sdj64's engine, as it was very similar to my own, but better. This craft has only a tiny amount of SAS because it's propellers spin opposite ways and tiny control surfaces. So unlike most turboprops it remains controllable and stable. It is a very early work but shows a lot of promise as an actual practical plane, I have another four engine cargo version as well that is almost finished which should be faster and be able to carry cargo. This is in stock aero, I even landed it, a broken prop doesn't count does it?

Download

 

 

[Gman_builder]

@selfish_meme How fast is that plane? I cant really see in the pictures

[selfish_meme]

1 minute ago, Gman_builder said:

@selfish_meme How fast is that plane? I cant really see in the pictures

at the moment with no cheats enabled and two full 1.25 to mk2 tanks and a couple of mk0's that are also full it can do about 60+ms, with a bit of trimming I can get the weight down again by quite a bit, and I think the engines could be tweaked further, there are only 6 junos in each, 88 parts and 7 tons wet. The bearing is sweet even better than mine was, but I guess if you wack some panthers on it you might upset it.

[Gman_builder]

5 hours ago, The Optimist said:

30 panthers

I wonder if a gear system would work. It probably wouldn't be very efficient if it did, due to KSP's *slightly* wonky physics engine, but it might let you make a larger gear turn the actual propeller much faster.

Well, if you've seen my car you should know that gears do work. But I don't think they work very well or even at all at the high speeds required to lift a helicopter. Also, keep in mind that the theoretical speed limit for props is around 50 RAD/s So I don't know how you'll achieve 4800 KN under the current limitations of KSP physics. Back to gears though, I think the problem arises in the collisions between the gear teeth. as they hit each other pretty hard even at low speeds. I used the structural panels because they have one of the highest crash tolerances. Wing segments and other similar parts with low crash tolerances don't work at all as gears.

Just now, selfish_meme said:

at the moment with no cheats enabled and two full 1.25 to mk2 tanks and a couple of mk0's that are also full it can do about 60+ms, with a bit of trimming I can get the weight down again by quite a bit, and I think the engines could be tweaked further, there are only 6 junos in each, 88 parts and 7 tons wet. The bearing is sweet even better than mine was, but I guess if you wack some panthers on it you might upset it.

I am not a fan of panthers in turboprop engines. They are to big. Keep in mind that Azimech and I are trying to promote setting the drag multiplier to 0 to keep the physics as close to what they were in 0.90. You'll have far more success and a good time if you set the drag multiplier to 0. You can also turn up your RPM limiter so your engines can spin faster.

[selfish_meme]

10 minutes ago, Gman_builder said:

Well, if you've seen my car you should know that gears do work. But I don't think they work very well or even at all at the high speeds required to lift a helicopter. Also, keep in mind that the theoretical speed limit for props is around 50 RAD/s So I don't know how you'll achieve 4800 KN under the current limitations of KSP physics. Back to gears though, I think the problem arises in the collisions between the gear teeth. as they hit each other pretty hard even at low speeds. I used the structural panels because they have one of the highest crash tolerances. Wing segments and other similar parts with low crash tolerances don't work at all as gears.

I am not a fan of panthers in turboprop engines. They are to big. Keep in mind that Azimech and I are trying to promote setting the drag multiplier to 0 to keep the physics as close to what they were in 0.90. You'll have far more success and a good time if you set the drag multiplier to 0. You can also turn up your RPM limiter so your engines can spin faster.

I am all for changing the stock settings for your speed contest, but I am more interested in building stuff that works for anyone who downloads it. I think its great that we could now use these engines for practical purposes and replicas.

[Gman_builder]

1 hour ago, selfish_meme said:

I am all for changing the stock settings for your speed contest, but I am more interested in building stuff that works for anyone who downloads it. I think its great that we could now use these engines for practical purposes and replicas.

I TOTALLY agree with you in all those aspects, but I was just saying if you want to get more performance you can change some stuff.

Yo Azimech, why does this happen?

 

Edited June 17, 2016 by Gman_builder