Kerbodyne SSTO Division: Omnibus Thread

[Kagame]

Can somebody pass the download link for the nuFAR dev build?

[blowfish]

Can somebody pass the download link for the nuFAR dev build?

Follow the source link in the OP to github, click "Download Repository." Extract the downloaded file and copy over the contents of GameData to your GameData folder.

[eddiew]

Er, not so great with the wave drag... I think it may be the sharp cut off at the back end that does it; the nacelles and main fuselage all stop at the same point and it drops down to the neck of the nerva and the control surfaces.

@Kagame; the download for FAR is listed on http://forum.kerbalspaceprogram.com/threads/20451-1-0-2-Ferram-Aerospace-Research-v0-15-Euler-5-8-15 - you can change to the dev branch via the github menu if you want

Edited May 12, 2015 by eddiew

[UnusualAttitude]

As an exercise in drag reduction, I've spent a couple of evenings trying to build another lo-tech standard jet spaceplane for my sort-of career game.

With the poor thrust of the standard jet you really have to reduce transonic drag, as you will be punching through the sound barrier on rockets, wasting precious fuel to go supersonic. It can be a pain, because just when you manage to get a stable airframe, you realize your wave drag area is high, and when you try and smooth it out by adjusting wing sections, etc... it ruins your stability.

Adding lumps here and there (small fuel tanks) can help, but it's mainly about the tail section where you may have a horizontal and vertical stabilizer in the same place (try and offset them slightly) or a vertical stabilizer in the same place as the widest part of a delta wing. For example in your design above Eddie; try offsetting the fin as far back as you can so it is above the rocket engine; this should reduce the huge dip you have in your second derivative curve (the yellow one). It will also improve yaw control . See pictures of Concorde to see what I mean.

A ridiculously pointy nose helps too... see how my wings and stabilizers are spread out along the length of the plane.

...and I finally found a use for the radial rockets!

Having said that, a 36-tonne spaceplane got me a mere 1.25 tonnes to a only-just LKO. I did it though...

[eddiew]

Getting anything to orbits with basic jets is pretty cool

Played with the transonic window a bit; pulling the tailplane back actually makes it worse, for reasons unclear :S But a tug on the wings and some fine optimisation of the canards dropped the wave drag to 3.2, and allowed a blistering 1470m/s on air. Better piloting might even have gone further, I was a bit aggressive on the ascent.

Alas, with a ship this small, twin rapiers really are the major fraction of the back end, and I can't reduce it further without a complete redesign. This is as far as she'll go with just tweaking.

Still, just chilling in orbit with 1038 delta-v... in mah tiny plane. There's still that hidden clipped fuel tank, but I figure it's made up for by the absence of oxidiser. Those rapiers don't get to switch mode, ever, they're just high altitude jet engines

Edited May 17, 2015 by eddiew

[blowfish]

Putting fuselage bumps in the right places seems to be able to reduce wave drag area significantly, though our planes might start to look like Mon Calamari Cruisers

[Wanderfound]

Got something cool on the way; self-sufficient Mk3 monster with a full ISRU scanning/drilling/processing rig in the bomb bay. Only needs four turbos to fly, too (plus a Mainsail for the orbital boost).

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Putting fuselage bumps in the right places seems to be able to reduce wave drag area significantly, though our planes might start to look like Mon Calamari Cruisers

This is making the need for a revived Kerbpaint even more acute; we need to be able to disguise those bumps will colour.

[FlipNascar]

Got something cool on the way; self-sufficient Mk3 monster with a full ISRU scanning/drilling/processing rig in the bomb bay. Only needs four turbos to fly, too (plus a Mainsail for the orbital boost).

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This is making the need for a revived Kerbpaint even more acute; we need to be able to disguise those bumps will colour.

[eddiew]

This is making the need for a revived Kerbpaint even more acute; we need to be able to disguise those bumps will colour.

Dragless internal lighting is an option now - make the lumps into features

(Yes yes, I forgot to move one of the lights inside the fuselage.)

And gah! I'm really torn between which aero model to use for my new career... Stock is friendly, and you simply can't crash a spaceplane, and you can fly fun looking things that don't work under nuFAR... but FAR is better for getting spaceplanes to orbit with enough delta-v to do useful things.

[Wanderfound]

Bugger efficiency, go with whatever's more fun.

I find the stock aero a bit too simplistic to be interesting, but each to their own.

[eddiew]

The problem is that efficiency is also fun I liked being able to build small(ish) SSTOs that could go land on Mun, drop off a rover, and return, without refuel, and it looks like nuFAR can probably deliver those again, with a bit of learning time... But I also like the funky shapes permitted by nuStock, which are just not viable under nuFAR.

Tough decisions

[Wanderfound]

Just to prove that a mid-wing airframe still works in nuFAR: Kerbodyne Tradizione.

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Craft file at https://www.dropbox.com/s/9violcj06dpq7nx/Kerbodyne%20Tradizione.craft?dl=0

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The problem is that efficiency is also fun I liked being able to build small(ish) SSTOs that could go land on Mun, drop off a rover, and return, without refuel, and it looks like nuFAR can probably deliver those again, with a bit of learning time...

Decent range in orbit is certainly doable; swap the central RAPIER on this one for a nuke and I suspect we're back to the good ol' days.

[Red Iron Crown]

I've been messing around with planes a lot more in 1.0 given the new stock aero system, and having followed this thread for a long time I was able to quickly meet with some success. Thanks, Wanderfound, for sharing all your designs and helping everyone else refine theirs.

A 6-seat crew transfer shuttle (I later added a probe core so I don't necessarily need a pilot):

A heavier cargo variant, can get a ~9-ton test payload to orbit with enough LFO to deorbit, plus some extra LF for atmospheric maneuvering:

As you can see, I like diamond-wing designs, the control surfaces from outside to inside are aileron, elevon, elevator. These are also the first planes I've done in a while that didn't need a utility compartment, the only non-aero part is an RTG hidden under the central airbrake of each. There's a bit of clipping of the intakes and fuel tanks, but I don't even feel bad because the aesthetic appeal makes up for it.

[Wanderfound]

I like what you've done with the shoulder intakes; looks nifty. That'd work well for FAR area ruling, too.

[Red Iron Crown]

I like what you've done with the shoulder intakes; looks nifty. That'd work well for FAR area ruling, too.

Thanks! I have to give credit where it is due, I stole the idea from tetryds when he showed me a plane he was working on for nuFAR (image). Basically, you just radially mount a reversed Mk2 bicoupler to the first fuselage, add intakes, then offset to your liking. It's vaguely cheaterish as the tanks intersect each other and much of the intake area is hidden, but it looks so good that I can forgive it. (The Rule of Cool seems to apply more to spaceplanes than rockets for me.)

[eddiew]

Just to prove that a mid-wing airframe still works in nuFAR: Kerbodyne Tradizione.

Very... traditional xD Good proof of point ^^

I've been messing around with planes a lot more in 1.0 given the new stock aero system, and having followed this thread for a long time I was able to quickly meet with some success. Thanks, Wanderfound, for sharing all your designs and helping everyone else refine theirs.

Those are rather nifty - the intakes are a cracking idea, and the diamond wings look like the might give a smooth cross section curve

Dunno whether anyone has verified whether the RAM intakes work better when they're angled to face the oncoming air flow? I heard a rumour about it, and it used to be true for B9's intakes, but not sure about the brave nuStock world...

[Wanderfound]

Kerbodyne Tradizione N. The old tricks still work.

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Craft file at https://www.dropbox.com/s/ms545zbicvou4xi/Kerbodyne%20Tradizione%20N.craft?dl=0

[Wanderfound]

Kerbodyne Gull NF. The Frenchman's egg.

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Craft file at https://www.dropbox.com/s/uzsjjsxjgnzs254/Kerbodyne%20Gull%20NF.craft?dl=0

[SHiftER2O]

Kerbodyne Tradizione N. The old tricks still work.

http://imgur.com/a/ZTlo3

Craft file at https://www.dropbox.com/s/ms545zbicvou4xi/Kerbodyne%20Tradizione%20N.craft?dl=0

What old tricks?

[eddiew]

What old tricks?

Wander likes his bird shaped planes And I agree that they are by and large easier to fly than deltas.

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Kerbodyne Gull NF. The Frenchman's egg.

1 engine

[SHiftER2O]

Wander likes his bird shaped planes And I agree that they are by and large easier to fly than deltas.

What are the properties of this "bird-plane" design?

[eddiew]

What are the properties of this "bird-plane" design?

See the planes above Basically a more conventional plane shape; mid wing and tail, with the optional of forward canards. Vs the very popular (in KSP) deltas which merge the wing and the tail into a single large surface which can be a simple triangle

or more complicated

.

Advantages of the bird shape:

- option for a dihedral slope on the tail (see both planes above) which gives some additional roll stability, making the plane prefer being horizontal on that axis.

- twice as many control surfaces, so you can dedicate the main wing to roll, and the tail to lift - or even have two pairs of dedicated spoilers.

- CoM is easier to move forwards, since you can place the engines in nacelles (see Tradizione N above), so rear control surfaces have more leverage

Disadvantages:

- doesn't "look" as fast

- potentially less streamlined? I guess Wander will have his own views on that. It can go either way; deltas can suffer a very sudden shut off at the back end, leading to wave drag. On the other hand, bird shapes are often wider overall.

Edited May 13, 2015 by eddiew

[Wanderfound]

What old tricks?

Eddie's got part of it, but I was mostly thinking of the RAPIER/nuke/RAPIER layout with lateral tanks and shock cones. Early tests with NuFAR suggested that sort of layout might be too draggy, and the reduced jet altitude ceiling makes nuke ships trickier to manage. For a while there, it looked like single-fuselage deltas were going to dominate.

[eddiew]

Everything works in nuFAR if you abuse clipping enough I wonder how many nacelles I can stack before it gets silly...

[Wanderfound]

Quite a bit of speed in the basic jet...