HX-1 Circular Wing Experiment. Or what happens when I fuse the Normandy with a Corellian Corvette.

[Goddess Bhavani]

Background:

I've always wanted to see if a 'biplane' could go supersonic. But, logic and common sense so far had dictated to me conventional aircraft wisdom was good to follow for most of my KSP career path. Until today.

I'm involved with a couple of major Facebook KSP groups and I often poke at mods and models in progress and see if I can lend a hand to testing them, particularly if it's someone learning to model for the first time.

It so happened the modeller I'm testing parts for right now shares a common interest in "planes that never flew" so I decided to screw common sense and construct a circular-winged spaceplane. Oh wait, I'm up to my usual sheninigans again after dreaming about intergalactic sheep, right?

Well, there actually is some sense behind wanting to use a closed wing design (i.e., annular or circular wing). You see, A Mark 3 spaceplane is not small. A normal delta planform usually has large issues with CoM shifting on the ascent phase due to fuel burn, mach effects, whatever. It also tends to have a very long takeoff roll. It's probably solvable by just throwing more control authority, thrust and wing area at the problem but I thought, why not halve the wingspan and double the wing area using a circular wing?

The result:

HX-1 "Artemis" hypersonic airliner concept

The HX-1 flew on its first try, and exceeded the sound barrier by several times. While CoM shifts are still present, they can be easily compensated for using manual flaps and/or trim. Insane as it sounds, it's possible to turn off SAS and let physics do its thing, as the circular wing proved to be extremely stable at both subsonic, and supersonic speeds.

Initially intending to construct something like the Normandy SR-1, I was soon dissuaded from the task by issues related to its extreme dihedral and the obvious thrust issues from placing the engines so far under the fuselage. It would also require actual mass effect drives for safe landings.

To solve the problem I just chopped off the back end of the ship and mated it with what looks like a Corellian Corvette style engine array of 8 turboramjets and 4 LVT-45s for maximum industrial light and sound effects. You know, I could also use 12x Rapiers but decided against it for the premise of gratitous afterburning effects.

She certainly would look good in Pan Am livery!

Future Plans:

The circular wings were constructed out of B9 Procedural Parts, as I didn't want to mess with multitudes of relatively small stock wing sections and having to strut them all up together. By the time I'm done with tying it up to corset levels of tightness, a lot of mass would be wasted on struts. Wheras with B9 PP I could focus on designing the plane first, and keep part count and strutting at a minimum.

Strutting about can be fun at certain social events, but not when there's mod parts to test! But if anyone's interested in seeing how circular wings work on a spaceplane, I'd gladly replace the custom cockpit with a standard Mk3 'space shuttle' unit and send a craft file your way.

Where does the cockpit come from?

It's from a parts mod in development, Mk3 Hypersonic by Nestor de Buen. Over the next few days he's working on texture issues, detail issues and developing an unmanned drone version of the Mk3 Hypersonic cockpit, as it will match the craft's aesthetics better. The B-36 style greenhouse cockpit is indeed inspired by the B-36.

Also, take heed, Romulans, you'll be building Warbirds this way in a few centuries!

Update 3 Aug:

Download the craft file from KerbalX! (B9 Procedural Parts required)

http://kerbalx.com/pandoraskitten/HX-1A-Artemis-Hypersonic-Transport

Video posted and featured on KSP Official Facebook Page!

Edited August 3, 2015 by pandoras kitten

[Jett_Quasar]

That is one of the coolest things I've seen - very unique.

JR

[CommanderSpock]

Can I have the file with the stock cockpit?

[Free Trader Beowulf]

That's one good looking ship - I'm definitely borrowing those drive pods when I get back to building airbreathers.

I don't know if it's modelled in KSP, I guess not, but closed wings like that also eliminate wing tip drag, which is non-trivial.

[Rune]

Yup, even in RL with complex interaction issues between lifting surfaces, that wingform would be perfectly fine. In KSP, were every part acts competely independant from the others, doubly so.

Rune. In other words, triplanes make great hypersonic planes here.

[Goddess Bhavani]

Can I have the file with the stock cockpit?

I looked at a few Community contributed spaceplanes and am now assembling a streamlined looking nose for this craft. Expect positive results or spontaneous disassembly soon.

In other news, the Mad Rocket Scientist has offered to help with making stock annular wings! I had an idea to pre-fabricate the swept back curved airfoil sections to minimize the headache of dealing with lots of little little parts, but we'll see if I have the time to make a 'quick' reverse engineering effort off the B9 proc wings pictured above.

Also thanks for all the rep and the positive feedback - it's nice to try interesting designs and learn a thing or two about experimental aero concepts

[CommanderSpock]

I'm looking forwards to it!

[Goddess Bhavani]

Good News Everyone!

Now you can experience the new circular wing airframe in the comfort of your standard Mk3 Cockpit! B9 Procedural Parts still needed for the circular wings.

Download Craft at KerbalX:

http://kerbalx.com/pandoraskitten/HX-1A-Artemis-Hypersonic-Transport

While I do up a video for this craft and its new stock cockpit variant, here's how it looks with the stock nose section. I 'streamlined' it a bit by welding a C7 2.5-1.25 adapter to the front and hitting it with a hammer repeatedly.

I also optimized the rocket engine thrust vector to allow for faster ascension to space with significantly less trim needed.

[selfish_meme]

You came to the same cockpit design I used, I posted it yesterday

[Goddess Bhavani]

You came to the same cockpit design I used, I posted it yesterday

Indeed I must have come to the same conclusion as you last night!

I laid out a whole assortment of adapters and got to work shoving them into the front of the plane and came out with only two possibilities - one was use the curved adapter to create a duckbill drone nose (which I then had trouble clipping Mk1 inline cockpits into), and the other was hammer the C7 adapter in and rotate randomly in small amounts until the clipping was reasonable. This looked pretty much identical to yours.

---

Moar update:

Full video:

Edited August 3, 2015 by pandoras kitten

[Azimech]

Beautiful ship, man!

[kreutzkevic]

Man,

I can't decide which is cooler: your HX-1 or your XRR 1-S...

Very well done.

[Goddess Bhavani]

Man,

I can't decide which is cooler: your HX-1 or your XRR 1-S...

Very well done.

Thanks for your kind compliments

This reminds me - I heard B9 has a dev version that is just about perfect for use in 1.0.4. Which means I can start to import my old craft and update them. Definitely the infamous "Rotary Rocket" will make a comeback, if only to strike terror in the hearts of test pilots

--

HX-1 update

It would appear I made a little engineering mistake when developing this craft. Like the real world Space Shuttle, the wing area is somewhat excessive for a craft of this size. I would have the option of making the airfoils smaller for a stock-ified build, or I could make the airframe larger and add some additional fuel and maybe even an externally-mounted payload to it.

I am thinking the circular wings lends for an interesting opportunity to see if HX-1 can accomodate a dorsally mounted second stage right above its center of mass, carry that stage and payload into a sub-orbital trajectory, launch it into a higher orbit, and then recover the plane at an airbase halfway around Kerbin. It may even be possible study those very interesting piggyback concepts studied in the early days of the Shuttle program.

Starting small, I will next attempt to mount one or two of my X-1 Micro Shuttles onto the HX-1 in various 'parasite' configurations. I'm thinking it's possible to attach them above the propulsion section above the main fuel tank. Since the X-1s can be configured to be 'self flying' payloads that produce their own lift, it should be quite practical once I design a streamlined 'docking station' for such payloads.

Edited August 3, 2015 by pandoras kitten

[B-STRK]

I think I'm in love with your ship. It's not creepy.

I'd vote for a stock-ified build, particularly for those that haven't the Procedural mods. (Although maybe I should download Pwings...)

And why won't this system let me give more rep?!

[Goddess Bhavani]

*gives a PM to the famous Mad Rocket Scientist to request stockification*

I think ima need some help with stockifying this one and I'm not afraid to ask - I would actually not mind if people take apart the plane and make something better out of it. Or make a smaller Mk2 or even Mk1 version for fun. It'll be fun to render a whole fleet of closed wing designs and see how they hold up in various mission types.

I think there is some design / thought lineage from earlier Kerbal aircraft replicas that led to this. It's interesting how an old STOL military observation craft would eventually lead to a futuristic 'biplane' after several months of daydreaming!

[SquaredSpekz]

Is this in Stock Aero or FAR? Because B9PP only works in FAR and if that's stock i'm wondering how.

[Goddess Bhavani]

Currently flying with stock aero. I thought to use stock aero as a basis for all craft now, since it's not dissimilar to old FAR.

[wgering]

That is a thing of beauty. What kind of payload capacity does it have?

[Goddess Bhavani]

That is a thing of beauty. What kind of payload capacity does it have?

Currently, I only did airframe proofing for the craft, which involved expanding the flight envelope gradually from supersonic, hypersonic, sub-orbital and then aiming for space. Currently I managed to attain orbit with a few hundred units of spare oxidizer and enough rocket fuel to last for LKO insertion plus a short supersonic flight to the nearest airport after re-entry.

However, I did that without carrying any RCS fuel or thrusters.

As mentioned in a previous post, it would appear the wing size for this craft is absurdly large especially considering the circular wing has doubled the effective wing area - this gives a lot of room to further develop the craft into an SSTO with a useful payload. I can develop in two areas -

One, I can simply make the main hull larger and add a Mk3 cargo bay, with more fuel (possibly extend the ramjet nacelles, add more 'wet' wing sections) and see how much she can bring into orbit. A larger (and possibly fatter, with conformal fuel tanks) ship of course wouldn't look as sleek but she will be more useful.

Two, I can retain the present hull configuration to serve as a baseline, 32 passenger tourist craft. I have the option of replacing the passenger modules with a cargo bay, or I can develop an aeroydnamic 'mission pod' to piggyback on top of the airframe, taking hints from the historical B-58 Hustler supersonic bomber which carried fuel and ordnance in an external pod.

The piggyback method is interesting as I can use the craft to loft a payload assist module into orbit or send a parasite spacecraft or two into space. Oversized payload can easily extend into the empty space within the circular airfoil.

So the projected payload for this design is yet to be determined - considering in the video I managed to takeoff with a "full" 160 ton configuration with barely 1/3 of the KSC runway, I believe this design has ample room to evolve.

Edited August 3, 2015 by pandoras kitten

[Mad Rocket Scientist]

*gives a PM to the famous Mad Rocket Scientist to request stockification*

Thanks!

- - - Updated - - -

Problems: B9 Wings aren't generating lift. Any ideas? I'm not using far.

[Mad Rocket Scientist]

Doesn't matter about the wings, it just means that I don't know how it flies, but I'll make it the best I can.

Here's a picture:

[CommanderSpock]

Looking good so far!

[Mad Rocket Scientist]

Uh oh...

- - - Updated - - -

It's almost taking off! How wobblely should it be?

[Mad Rocket Scientist]

It's flying! It flies like a drunken, fat, pig, but it DOES fly. 200m/s@5,000m. No, that's not an email address. At least, I don't think it is.

- - - Updated - - -

275m/s@8500m.

- - - Updated - - -

300m/s(mach1)@aprox.10,000m.

- - - Updated - - -

400m/s@13,500.

[Goddess Bhavani]

Lol I'm surprised to hear B9 wings aren't generating lift. Mine must be powered by magic or something. I kind of forgot B9 is supposed to only play nice with FAR but then it flew beyond expectations the first time and I left it as it is.

The stockification is looking good! I'm surprised the big aeroplane wings can be swept back so far, and they're just the right size for this application. There's that funny right angle at the lower leading edge of the circular section though - maybe Bill needs to take a file for final fit and finish

How is the takeoff speed using stock parts? With B9 (Somehow without FAR) it takes off very easily right where the control tower is. If your takeoff distance is close we can estimate roughly the same lift/drag ratio. In the original config the plane is a bit of a pig at low altitude but starts to break the sound barrier on turboramjets in a steady climb above 8,000m.