Fastest Juno-powered aircraft

[Andetch]

On 6/22/2018 at 6:58 PM, Aetharan said:

My second attempt went slightly better, managing a successful landing after circumnavigation under the same self-imposed rules: 2 passengers, no dive-bombing for speed, and complete circumnavigation to demonstrate usefulness as a light transport.

https://imgur.com/a/nhnlD9S

Top speed is 630 m/s, and this time, I have a craft file if anybody wants to fly it.  https://kerbalx.com/aetharan/AAC-630-Leer

I think this could probably win you a Kerbin Circumnavigation badge too

(If you haven't already?)

[Aetharan]

@RealKerbal3x Sadly, the design holds 1/5 the number of passengers KEA wants for a supersonic plane.

@Andetch  That badge, I earned a long time ago, but I appreciate the mention nonetheless.

[Andetch]

Either way, I like and agree with making an entry functional. Not sure how far my entries would go (I launch with bare minimal fuel), but I tried to make sure they both worked as an aircraft rather than just a capsule plus engines!

Edited June 24, 2018 by Andetch

[Aetharan]

@Andetch It was your comment on the previous page that convinced me to build a functional plane instead of lobbing a capsule.

[Andetch]

6 minutes ago, Aetharan said:

@Andetch It was your comment on the previous page that convinced me to build a functional plane instead of lobbing a capsule.

Yay, I had influence! (Oh, and I see your badges now - I was on my phone before and couldn't see the badge)

Edited June 24, 2018 by Andetch

[RealKerbal3x]

3 hours ago, Andetch said:

Yay, I had influence! (Oh, and I see your badges now - I was on my phone before and couldn't see the badge)

Mobile can be very annoying for this forum

[Lisias]

It wasn't meant for this Challenge, but it happened that the thing performed very well for this task. Still trimming it, but I got ~540m/s ar 15.000 Meters high in level flight.

Not enough to enter the boards on a decent place, but not bad anyway - way better than I was expecting at least.

 

Edited June 24, 2018 by Lisias

[RealKerbal3x]

38 minutes ago, Lisias said:

It wasn't meant for this Challenge, but it happened that the thing performed very well for this task. Still trimming it, but I got ~540m/s ar 15.000 Meters high in level flight.

Not enough to enter the boards on a decent place, but not bad anyway - way better than I was expecting at least.

 

Nice, but the cockpit you’re using isn’t stock, so it’s not eligible unfortunately. The rules say it must be stock to keep it a level playing field. Sorry

[Lisias]

1 hour ago, RealKerbal3x said:

Nice, but the cockpit you’re using isn’t stock, so it’s not eligible unfortunately. The rules say it must be stock to keep it a level playing field. Sorry

Whoops… My bad! I will fix this.

[RealKerbal3x]

Just now, Lisias said:

Whoops… My bad! I will fix this.

No worries— I put that rule there so people wouldn’t try to use massively OP parts like super-lightweight fuel tanks or something. Basically so everyone has the same stuff to work with.

[The Minmus Derp]

What if you do this with GPO? It replaces Kerbin, and has a SLIGHTLY thinner atmo.

[RealKerbal3x]

9 hours ago, The Minmus Derp said:

What if you do this with GPO? It replaces Kerbin, and has a SLIGHTLY thinner atmo.

Hmm, I suppose it’s OK as long as it’s a Kerbin twin in most other ways.

[Lisias]

15 hours ago, RealKerbal3x said:

No worries— I put that rule there so people wouldn’t try to use massively OP parts like super-lightweight fuel tanks or something. Basically so everyone has the same stuff to work with.

I see your point, I had to heavily rework the craft! I managed to get it faster, but terribly unstable. Interesting, I need to better investigate the changes some mods do on the parts and/or game physics or I will err again.

Anyway, here comes my (proper) entry: ~611 m/s on a controlled descent, 565 m/s @ 5322 meters high (sort of) level flight - it's extremely hard to keep this babe flying straight, she's highly unstable above Mach 1.3 or 1.4, and Inertial Decoupling haunts us after that.

Craft here (Kerbal-X).

Edited June 25, 2018 by Lisias
"My God! It's full of grammar mistakes…."

[RealKerbal3x]

2 minutes ago, Lisias said:

I see your point, I had to heavily rework the craft! I managed to get it faster, but terribly unstable. Interesting, I need to better investigate the changes some mods do on the parts and/or game physics or I will err again.

Anyway, here came my (proper) entry: ~611 m/s on a controlled descent, 565 m/s @ 5322 meters high (sort of) level flight - it's extremely  to keep this babe flying straight, she's highly unstable above Mach 1.3 or 1.4, and Inertial Decoupling haunts us after that.

Craft here (Kerbal-X).

Okay, good job! It is interesting though how your plane flew OK with mod parts but was unstable with stock parts. KSP physics can be weird 

[Andetch]

3 hours ago, Lisias said:

I see your point, I had to heavily rework the craft! I managed to get it faster, but terribly unstable

 

Stability issues most likely caused by a shift in the CoM/CoL alignments, (note the wings now have a forward strake) plus all the added drag from the new air intakes? 

[Lisias]

On 6/25/2018 at 7:20 AM, Andetch said:

Stability issues most likely caused by a shift in the CoM/CoL alignments, (note the wings now have a forward strake) plus all the added drag from the new air intakes? 

Yes, that was an issue. It's the reason I used a forward strake wing and rearranged the engines position on the Z axis. (MechJeb to the rescue, this mod have an option to visualize CoL, CoM and CoT live!). 

That helped, but only below Mach 1.3 or 1.4 . Drag appears to not be an issue, neither Engine Torque (I almost zeroed the torque - see the KER window on the SPH screenshot).

My current guess is Inertial Decoupling (I had read somewhere else that KSP appears to simulate this, and this vessel is light), and lift generated by the hull (the cyan vectors on Aerodynamic Forces Display) - if the craft "shatters" enough, one (or both) these issues kicks and the craft spins so crazily that would make Chuck Yeager proud (yeah, I watched "The Right Stuff"). The huge TWR (almost 2.0) saved my butter more than once.

I think I need bigger control surfaces, but for this challenge I was unable to use TweakScale so I didn't bothered to try. Control Surfaces on the main wings didn't helped at all, au contraire - using canards *and* wing-tail appears to give some good results on short length aircrafts - at least under Mach 1.4 (they can be the reason the aircraft became unstable at high speeds, it's hard to synchronize both sets of control surfaces, MechJeb's autopilot can't handle them…). I intend to further investigate this thesis.

p.s.: The Landing Gears need trimming too, but I didn't fix them, as they're not needed for the challenge…  

p.s.2: I fired up the thing again, and noticed that the shattering starts when the Atmospheric Efficiency approaches 100%, and become progressively worse as it goes above 100%.

ps.3.: I had a hunch and set the Max Physics Delta-Time pre Frame to 0.03 and the vessel became slightly easy to control. The shattering is gone, and a slight oscillation is happening now. It's easier to make her loose the equilibrium, bank too much and stall (what is the name of this in EN? Can't remember) above Atmospheric Efficiency 150%. So that "shatter" was rounding errors while rendering the Physics calculations.  

Still, no AutoPilot can handle her - but now I can "see" things going through the tubes. So, yeah. Autopilots can't handle pitch on canards *and* stabilizers at the same time.

Edited July 1, 2018 by Lisias
more data.

[RealKerbal3x]

30 minutes ago, Lisias said:

Yes, that was an issue. It's the reason I used a forward strake wing and rearranged the engines position on the Z axis. (MechJeb to the rescue, this mod have an option to visualize CoL, CoM and CoT live!). 

That helped, but only below Mach 1.3 or 1.4 . Drag appears to not be an issue, neither Engine Torque (I almost zeroed the torque - see the KER window on the SPH screenshot).

My current guess is Inertial Decoupling (I had read somewhere else that KSP appears to simulate this, and this vessel is light), and lift generated by the hull (the cyan vectors on Aerodynamic Forces Display) - if the craft "shatters" enough, one (or both) these issues kicks and the craft spins so crazily that would make Chuck Yeager proud (yeah, I watched "The Right Stuff"). The huge TWR (almost 2.0) saved my butter more than once.

 I think I need bigger control surfaces, but for this challenge I was unable to use TweakScale so I didn't bothered to try. Control Surfaces on the main wings didn't helped at all, au contraire - using canards *and* wing-tail appears to give some good results on short length aircrafts - at least under Mach 1.4 (they can be the reason the aircraft became unstable at high speeds, it's hard to synchronize both sets of control surfaces, MechJeb's autopilot can't handle them…). I intend to further investigate this thesis.

p.s.: The Landing Gears need trimming too, but I didn't fix them, as they're not needed for the challenge…  

p.s.2: I fired up the thing again, and noticed that the shattering starts when the Atmospheric Efficiency approaches 100%, and become progressively worse as it goes above 100%.

...and this is why we have revert and quickload. Neither Chuck nor NASA had any of those benefits.

[RealKerbal3x]

No one's posted here in a while so just remember that you can still enter! There's no deadline

[The Minmus Derp]

3 hours ago, RealKerbal3x said:

No one's posted here in a while so just remember that you can still enter! There's no deadline

Well yeah. You should include big bright letters: NO DEADLINE.

[RealKerbal3x]

20 hours ago, The Minmus Derp said:

Well yeah. You should include big bright letters: NO DEADLINE.

I assumed people would read the first post before they entered, and it doesn't say there's no deadline anywhere.

[Lisias]

I'm trying to update my design to reach Mach2 on my career. More specifically, 685 m/s (it's a GAP mission I think). 

Currently, i'm stuck at 675...

As soon as I manage this stunt, I will rework it for stock and update my entry. 

This is being quite a challenge, every extra m/s is a fight for death!

 

Edited July 1, 2018 by Lisias

[RealKerbal3x]

21 minutes ago, Lisias said:

I'm trying to update my design to reach Mach2 on my career. More specifically, 685 m/s (it's a GAP mission I think). 

Currently, i'm stuck at 675...

As soon as I manage this stunt, I will rework it for stock and update my entry. 

This is being quite a challenge, every extra m/s is a fight for death!

 

You can doo eeet!

[Lisias]

Just now, RealKerbal3x said:

You can doo eeet!

Eventually, if I manage to avoid running out of runways.  

[RealKerbal3x]

Just now, Lisias said:

Eventually, if I manage to avoid running out of runways.  

Hehe. You've posted that pic so many times I'm surprised it's not your profile picture by now

[Andetch]

2 hours ago, RealKerbal3x said:

I assumed people would read the first post before they entered, and it doesn't say there's no deadline anywhere.

Yeah, that was your mistake...... reading, pah!

2 hours ago, Lisias said:

I'm trying to update my design to reach Mach2 on my career. More specifically, 685 m/s (it's a GAP mission I think). 

Currently, i'm stuck at 675...

As soon as I manage this stunt, I will rework it for stock and update my entry. 

This is being quite a challenge, every extra m/s is a fight for death!

 

I know how hard it can be squeezing a few m/s more from a craft! I need 18 m/s more too. Currently getting 2 m/s more. (So my best is actually 803 m/s)