Fastest Juno-powered aircraft

[Andetch]

31 minutes ago, RealKerbal3x said:

About the command seat issue @Andetch mentioned..... @swjr-swis could you post a screenshot to confirm that the craft is occupied? It must be actually manned for your entry....just having an empty cockpit/command seat does not make it eligible for the manned category. Just checking

@swjr-swis already blew my complaint out of the water! Notice that there is EVA propellant showing in the resources tab. This only happens with a Kerbal in EVA or a Command seat. I should have been smart enough to see it myself really... You can test it easily enough by putting a command seat on top of a capsule with a rocket on it and go EVA to the seat and fire up the rocket engine from the seat. It will show the EVA Prop. 
Makes me wonder why there is a probe core in the design though... but anyway.... I will have to settle for 2nd again until Nesty comes around to beat me some more.... 

[RealKerbal3x]

Just now, Andetch said:

@swjr-swis already blew my complaint out of the water! Notice that there is EVA propellant showing in the resources tab. This only happens with a Kerbal in EVA or a Command seat. I should have been smart enough to see it myself really... You can test it easily enough by putting a command seat on top of a capsule with a rocket on it and go EVA to the seat and fire up the rocket engine from the seat. It will show the EVA Prop. 
Makes me wonder why there is a probe core in the design though... but anyway.... I will have to settle for 2nd again until Nesty comes around to beat me some more.... 

And that's what happens when you don't pay enough attention......should have noticed that!!! Well, problem solved

[Andetch]

 

41 minutes ago, RealKerbal3x said:

And that's what happens when you don't pay enough attention......should have noticed that!!! Well, problem solved

It's easy enough to do (a damned-sight easier than squeezing an extra 25 m/s from my initial design, now I gotta get 20 m/s more from the current speedbird) - it just so happened he was posting on the thread at the exact time I was putting up mine so the query and answer are right next to each other, within seconds! 

Edited June 19, 2018 by Andetch

[swjr-swis]

1 hour ago, Andetch said:

Makes me wonder why there is a probe core in the design though

Two reasons: force of habit, and because I could.

I play with G-force effects enabled, so I always put a probe core in my craft to keep control when the pilots pass out. This craft doesn't just fly in a straight line, it can also bank and loop-the-loop at ludicrous speeds without breaking up - many kerbal lives were (temporarily) saved by that core while testing the capabilities of the craft.

Additionally, since the core is shielded from drag anyway, and the craft has more power than it really needs (l simply copied the outer ring engine subassembly from the 3b version, and it so happened to make a pleasing arrangement), removing the core to minimize drag/mass was not required to allow max speed.

[Andetch]

So what you're really saying is that this is like a rollercoaster and the pilot is optional, hahahaha! I'm going to squeeze another 20 m/s from mine

[Klapaucius]

This jalopy is far from taking the prize, BUT I did manage to get it to 545 while climbing.  It took several minutes, and it seemed to prefer flying upside down. It maxed out around 570 in a very shallow descent.  I'm quite proud of that since I knocked three engines off on takeoff...

 

 

 

[Andetch]

@Klapaucius it is the first 2 seat model! 

[Klapaucius]

3 hours ago, Andetch said:

@Klapaucius it is the first 2 seat model! 

Ugh, that sounded like a challenge, so I lost another hour coming up with this. Only around 320 mps, but it can carry 14 and a lot of fuel!  There are 21 Junos, so I've got a 1.5 Juno per passenger ratio.  Is that good???? 

I was supposed to be working from home, so I guess I'll be finishing up through dinnertime  (And knowing me, I'll be tweaking it for the next week until I relent and post it on KerbalX).

 

[RealKerbal3x]

@Klapaucius yes, you have the first 2-seat entry!

I’ll stick you on the leaderboard tonight

[Andetch]

2 hours ago, Klapaucius said:

There are 21 Junos, 

Lol, my 801 m/s has 24 engines! And a passenger count of 1!! May I suggest adding MOAR ENGINES!

Edited June 20, 2018 by Andetch

[Klapaucius]

28 minutes ago, Andetch said:

Lol, my 801 m/s has 24 engines! And a passenger count of 1!! May I suggest adding MOAR ENGINES!

Yeah, it was not nearly enough. After I replied to you I went back and mucked around.  I copied the wing and engine assembly and slapped it on the bottom. So, 41!  Will cruise over 300, can get up to 450 in a dive and carries 22. It needs some touching up; the workmanship is a bit slapdash...

 

Edited June 20, 2018 by Klapaucius

[Andetch]

1 hour ago, Klapaucius said:

Yeah, it was not nearly enough. After I replied to you I went back and mucked around.  I copied the wing and engine assembly and slapped it on the bottom. So, 41!  Will cruise over 300, can get up to 450 in a dive and carries 22. It needs some touching up; the workmanship is a bit slapdash...

So...... another wing/engine assy to be added - merge them all together so it is one to reduce drag (maybe?) and optimize the air intakes so there is only just enough (again to minimize drag, you have some subsonic intakes there that are probably only adding drag at high speed), and empty the tanks so it only has enough fuel for one run (you notice mine launches with 60 out of a possible 1,400 units of fuel) to increase the TWR and I am sure you will be hitting 600+ soon  

[Klapaucius]

2 minutes ago, Andetch said:

So...... another wing/engine assy to be added - merge them all together so it is one to reduce drag (maybe?) and optimize the air intakes so there is only just enough (again to minimize drag, you have some subsonic intakes there that are probably only adding drag at high speed), and empty the tanks so it only has enough fuel for one run (you notice mine launches with 60 out of a possible 1,400 units of fuel) to increase the TWR and I am sure you will be hitting 600+ soon  

I was going for cool over practical, but will give it a go :-)

[Andetch]

18 minutes ago, Klapaucius said:

I was going for cool over practical, but will give it a go :-)

At least flying with a lower fuel count will increase the speed

[RealKerbal3x]

4 hours ago, Klapaucius said:

Yeah, it was not nearly enough. After I replied to you I went back and mucked around.  I copied the wing and engine assembly and slapped it on the bottom. So, 41!  Will cruise over 300, can get up to 450 in a dive and carries 22. It needs some touching up; the workmanship is a bit slapdash...



 

So maybe we need a 'Juno Airlines' category where you have to transport as many kerbals as far as possible and as fast as possible.

But that's for another challenge I guess. This one will remain with only manned and probe categories and if you choose manned you can have as many kerbals as you want.

[Klapaucius]

11 minutes ago, RealKerbal3x said:

So maybe we need a 'Juno Airlines' category where you have to transport as many kerbals as far as possible and as fast as possible.

But that's for another challenge I guess. This one will remain with only manned and probe categories and if you choose manned you can have as many kerbals as you want.

Yes, it was a self-imposed challenge after I submitted the first. But that's the fun bit, eh? A challenge comes and sets you off on a new creative tangent.

[swjr-swis]

1 hour ago, Andetch said:

merge them all together so it is one to reduce drag (maybe?)

Does not work. Heat and drag are treated very differently in KSP. To the game, parts are fully 'transparent' to drag, regardless of how they are attached or what's 'in front of' or around them, with the exception of bays/fairings.

The things that do matter:

• shielding inside a bay or fairing (but not always! I'm looking at you, Mk2 bay corner spaces and wheels/gear)
• plugging stack attachment nodes (don't forget engines with bottom attachment nodes)
• making opposite nodes as similar as possible (some 'size X' nodes are more equal than others)
• minimizing the cross-section size and nr. of stacks
• placing parts as 'prograde' as possible (even when it visually -and logically- looks like that would only cause more drag - like most radially attached parts on cones)
• choosing the least draggy top/bottom stack parts
• angle of incidence on wings... seriously (keep the body of the craft prograde)
• make full use of the in-game Physics/Aero displays to find out the counter-intuitive results of tweaks on your design (less/smaller parts = more drag, sometimes )

It's not simply a matter of adding more engines. It's been tried. Ever since the Juno was introduced.

Spoiler

Some experimenting was done, back in 1.0.5. Fun was had. At least, she looked like she was having fun.

The G-Star - the instinctual kerbal answer to the question 'how much faster can we make this go'. 1 command seat, 6 wings, 151 intakes and Junos.

Full album here.

 

[Andetch]

35 minutes ago, swjr-swis said:

Does not work. Heat and drag are treated very differently in KSP. To the game, parts are fully 'transparent' to drag, regardless of how they are attached or what's 'in front of' or around them, with the exception of bays/fairings.

The things that do matter:

• shielding inside a bay or fairing (but not always! I'm looking at you, Mk2 bay corner spaces and wheels/gear)
• plugging stack attachment nodes (don't forget engines with bottom attachment nodes)
• making opposite nodes as similar as possible (some 'size X' nodes are more equal than others)
• minimizing the cross-section size and nr. of stacks
• placing parts as 'prograde' as possible (even when it visually -and logically- looks like that would only cause more drag - like most radially attached parts on cones)
• choosing the least draggy top/bottom stack parts
• angle of incidence on wings... seriously (keep the body of the craft prograde)
• make full use of the in-game Physics/Aero displays to find out the counter-intuitive results of tweaks on your design (less/smaller parts = more drag, sometimes )

It's not simply a matter of adding more engines. It's been tried. Ever since the Juno was introduced.

 

Hmm, interesting, as I found on my attempt that by moving the engine/tank/nosecone assembly inside the intake part it reduced the drag (or increased the speed) significantly. Also, when I removed the nosecone pieces from the tank parts it slowed it down again (increased drag). Adding more engines also helped, as long as they were moved to align with the existing ones. The other big difference was using the fairing as the nose (it still appears to be drag free).... I know the early KSP had a very illogical aerodynamics engine, but has it been improved since? I am on 1.4 now.....

[RealKerbal3x]

Good discussion going on here....and @Klapaucius I've added you to the leaderboard.

Currently the fastest person of this challenge is @swjr-swis at 820 m/s with a manned craft. I wonder if this is beatable, or has he reached the limit of Juno-speed?

1 hour ago, swjr-swis said:

Does not work. Heat and drag are treated very differently in KSP. To the game, parts are fully 'transparent' to drag, regardless of how they are attached or what's 'in front of' or around them, with the exception of bays/fairings.

The things that do matter:

• shielding inside a bay or fairing (but not always! I'm looking at you, Mk2 bay corner spaces and wheels/gear)
• plugging stack attachment nodes (don't forget engines with bottom attachment nodes)
• making opposite nodes as similar as possible (some 'size X' nodes are more equal than others)
• minimizing the cross-section size and nr. of stacks
• placing parts as 'prograde' as possible (even when it visually -and logically- looks like that would only cause more drag - like most radially attached parts on cones)
• choosing the least draggy top/bottom stack parts
• angle of incidence on wings... seriously (keep the body of the craft prograde)
• make full use of the in-game Physics/Aero displays to find out the counter-intuitive results of tweaks on your design (less/smaller parts = more drag, sometimes )

It's not simply a matter of adding more engines. It's been tried. Ever since the Juno was introduced.

    Hide contents

Some experimenting was done, back in 1.0.5. Fun was had. At least, she looked like she was having fun.

The G-Star - the instinctual kerbal answer to the question 'how much faster can we make this go'. 1 command seat, 6 wings, 151 intakes and Junos.

Full album here.

 

Like a starfish!

Noice.

[swjr-swis]

41 minutes ago, Andetch said:

Hmm, interesting, as I found on my attempt that by moving the engine/tank/nosecone assembly inside the intake part it reduced the drag (or increased the speed) significantly.

The placement really doesn't matter, at least up to 1.3.1, but I'm quite sure they did not change that in 1.4 either. Something else must account for the difference you noticed.

A quick test to prove it to yourself:

Spoiler

A simple craft to test whether embedding parts into each other has any effect on drag. The same assembly of small nose cone, tank and engine is radially attached and offset to different places, including one dead center inside the 1.25m tank. All of them get subjected to identical drag, despite some being out in the open and others being half or even fully embedded in a bigger part.

There is a tiny difference on the right ones: the craft is slightly veering to the left, causing the very right part of the craft to travel through slightly faster airflow due to the curve = a tiny bit more drag.

Notice also that counter to what would be expected, the bottom right nose cone is suffering more drag than the top right one - showing that the only thing that is significant is the distance to the CoM (bottom right cone is furthest away from the pivot point, so subject to the fastest airflow due to the slight curve to the left).

 

[Andetch]

13 minutes ago, swjr-swis said:

The placement really doesn't matter, at least up to 1.3.1, but I'm quite sure they did not change that in 1.4 either. Something else must account for the difference you noticed.

A quick test to prove it to yourself:

Yeah, I have been inspired by your comments and been testing. Changing the angle of the wings makes it too unstable to take off it they go one way, and slows it down the other way (as it makes the nose sit just above centre prograde - good reserch for my next entry for Kerbal Express Airways) but using the overlay (not the tech readout that you have there, just the red lines) I am not getting any difference in the amount of red lines/size of lines. Putting a nosecone onto the node that is still available in the centre of the craft did reduce the drag line, but the weight made the craft slower (I think it was that?) Again, I salute your KSPertise! 

Good old KSP Not Quite Physics, eh?

Edited June 20, 2018 by Andetch

[Klapaucius]

On 6/17/2018 at 6:46 AM, Andetch said:

No, I simply put moar engines on it. I initially used a Mk1 capsule also to try and claim I wasn't copying but ditched the idea. 

I am still learning the finer points of ksp drag. For example it is only recently that I have started putting anger onto wings etc. (After reading a guide in the original KEA thread)

Can you post the link? I'd like to read that.

[Klapaucius]

On 6/20/2018 at 3:03 AM, RealKerbal3x said:

Serious respect to you if you can make a Mk3 aircraft powered only by Junos though...

I just slapped a few on this little seaplane I have been working on (usually it uses two ramjets).  With the wing tanks empty, I can get off the ground, but it did not want to stay there. With 4, I can get off the ground with full wing tanks and cruise at about 50.  With more....

 

Anyway, I've posted enough planes that don't fit the challenge, so I'll resist the temptation to do any more...

Edited June 20, 2018 by Klapaucius

[swjr-swis]

2 minutes ago, Klapaucius said:

With more....

4 is plenty.

Spoiler

The Dodo. A bird long believed to be extinct. And yet...

..contrary to popular belief, they actually fly.

 

[neistridlar]

I'd like to claim my second place on the probe core leader board: 813m/s, using only 7 junos.

And my second place for the manned category: 818.4m/s This was intended as a way to break the 820m/s limit, though I have not managed to do so yet.

This is what the craft looks like at launch:

It flies almost straight up, then ditches the junos when they flame out. It reaches 37km altitude and free falls back down. In theory it should be able to reach 850m/s without air resistance from that height, so it might be possible to break the 820m/s limit this way. And in case anyone wonders, the shock cone on the back is purely for drag reasons, it does not provide any meaningful amount of air to the engines.

@Andetch If you want me to I'll beat you in manned level flight as well .

Edited June 20, 2018 by neistridlar
Posted the wrong screenshot for max maned speed