Delta wings

[lizzienewell]

This is not an airplane but a marine vessel, an ekronaplan. When I showed this awhile ago I found out that most ekronaplans have reverse delta wings so I'm working on redesigning the wings.

Here is my first attempt at reverse delta wings. I haven't yet put the skin on because I've got some problems with the relation of the wings to the fusalage. You can see that the innermost former comes up to high and conflicts with the propulsors. I'm also unsure of the length fore to aft and of the angle; the wing is coming in below the hull in the stern of the craft which meansthe wings are going to be underwater when the craft lands(splashes down). Also the wing covers the orca markings on the fusalage. Yet the profile of the wing is rather intersting. I'm not sure if I should redesign the wing, the fusalage or both. Maybe the wing doesn't need to reach back quite that far.

Since this is not an airplane but a flying boat the wings are anhedral that means that they slope downward instead of upward as they do on an airplane.

 

[lizzienewell]

What no comments?
I guess I should have posted this in with the airplanes or with science-fiction.

 

[Bluenoser]

Why not remove the propulsors from their current location and incorporate them into the wing at the root (near the fuselage) between the two exposed wing ribs.
The move the entire wing assembly higher up on the fuselage. This will be possible because the removal of the propulsors from the fuse will have freed up some realestate for you to put the wings there. Now the wings won't be under the water and the orca hull can support the craft on the water. Actually, you have enough anhedral that your wing tips will likely be submerged. You could give them a gull wing profile (like on the WWII corsair) and bring the wing extentions up at the joint. This will keep all the wing out of the water with the exception of kink at where the wing changes direction. This point could incorporate a torpedo like pontoon for additional stability of the craft on the water.

 

[wunwinglow]

Quite a few aircraft have anhedral, or, like the Stuka and F4U, both, or like the B25 and a lot of gliders, are gull-winged, with the inner portion going up, outer panels down, or level!

Another notable feature of ekranoplans is the MASSIVE tail surfaces. The change of pitch trim is huge over the speed range, and so requires a big tail to generate enough force to keep the 'vessel' level. A big problem related to this is the speed that control effort needs to be applied, all the Russian types had automatic trim controls; failure of these was usually catastrophic, flying so fast and so close to the surface.

Fascinating devices!

Tim P

 

[hpept]

hi lizzie,
since you're asking for posts, here is mine. I like your designs which are mostly beautiful for fantasy vehicles. But they are a little far from being working machines in real world. I'll enumerate some points which you may consider to improve your design.

First point: how this machine would be supposed to "take off"? From the picture it seems that wing tips are far below the hull plane, so they would be the last to leave the water surface during take off. This is not safe, as a little roll during this phase would result in a catastrophic spin around the immersed tip. Since this is not an aircraft, it's supposed to float very close to water surface. Usually the "ground effect" takes place at a a distance from water which is considerbly shorter than wing span, let's say in the range of the wing cord distance. Working at this altitude, wing tips pointing down are still dangerous for the same reason as above, expecially with wavy sea.

Second point: engines location. Unless they are an unknown type of engines, they should be located as far as possible from water to avoid water feeding in the inlets. Usually they are located over the fuselage or in the wings(with high wing config) or in the vertical stabilizer.

Third point: fuselage is definitely too short. You have designed a very big tail surface, which involves big aerodynamic torque. The stability margin of this configuration would be rather poor, expecially if longitudinal control is simply a pilot task. (With a computer controlled system this could still work, but i guess no major aeronautic industry would design it this way). A longer fuseluge would reduce the strength needed to control the pitch, reducing tail surface (less drag, less weight) and as a side effect, also an increase of payload capability of the vehicle.

Hope this is useful to get even better designs.

 

[46rob]

Well Roberto's an aeronautical engineer, and all his points are valid....but your model is a bit of a fantasy design--so you don't have to be anatomically correct, if you don't want to be.

If this were my design, I think I'd raise the wing to a shoulder wing configuration--you'll trap more air and be more efficient, and I'd reduce the thickness of the wing. Let the wing come back around the vertical fin. Most pictures of real ones show a high winged design. Some have engines mounted in front of the wing and angled to force the jet blast under the wing. You could attach your propulsion units to the forward fuselage, on pylons, at a 45 degree angle, oriented to send the thrust slightly downward.

 

[lizzienewell]

You guys are right this is a fantasy vehical so it's more important than it looks cool than that the math comes out right on the engineering. I sure like your help on this.

My original concept was to give this hyrofoil landing gear and in my written descriptions they have this. I haven't got to working out how to design it yet. I sort of work on one thing at a time.

I concieve of this as a flying kayak which is why I located the propulsors and wings this why. I do want to try some with them in a different location. My original concept is to make a plane that could do an "eskimo" roll in the event of a capsize. The wings need to go underwater for this and I seperated the propulsors from wings to allow the wings to be brought closer to center of gravity for the roll. The commercial ekronoplan put out by Flightship does have pontoons on the wings so that the wings are the last thing to leave the water. I didn't want to do that because of interference with an underwater roll.

I concieve of these as being used for patrol by people regulating fisheries and gathering data on oceanography. They are for getting a few people around and so don't need a big payload, perfect for the US Park Service at Glacier Bay National Park. This park can only be reached by boat or airplane. The rangers patrol in a floatplane of some sort.
The propulsors are some sort of fictional technology that runs off something like a fuel cell and spits out something. I want them cool as close to solid state as possible and the less said about them the better.
The craft has an computerized stability system along with control through a wireless implant in the brain of the pilot. This gives the pilot the sensation of being the craft and gives him a faster reaction time. A kayak isn 't very stable but it is the best craft for tricky water because it's manuverable and responsive.
The thickness of the wings is to give me enough room to put the hinges in rather than being true to scale. This is a concept model rather than a scale model. As I describe my craft being used the anhedral/diahedral can be changed. I don't want to do this on the model because you really wouldn't be able to see it and it adds more complication in building and one more thing to fuss with when photographing the model.
The Russian design of ekronaplans seems to be that bigger is better in that a bigger ekronaplan is more stable and will carry more load. I think I'm taking this in the opposite direction.

Here is a photo of the Flightship which is a commercially available WIG craft. I'm roughly basing my desing on this but making it smaller, with warpable wings and with science-fiction propulsors.

 

[lizzienewell]

Here is another real craft that has some similarity to what I'm doing. This is the Lake Bucaneer. I was really excited the first time I saw one of these. I'd already been working on my models and was doing some photography. The Bucaneer was flying in almost the same place where I was imagining my fictional craft.

Interesting the Bucaneer does have the propulsion mounted on a pedestal above the fusalage. It also has higher wings as you guys mentioned.
In comparing the Bucaneer to the flightship I notice that they both have wing floats. The ones on the Flightship are more ellegant in that they are more integral to the wing.

I think that maybe my craft allow the wing to act as a hydrofoil. It should have the fan part of the wings adjust so that it is closer to the Flightship wing shape. Ugh. In practical terms it's going to be really tough to build that part (the wrist). It's currently make of strip styrene and it's easiest to make coming out flat. I've already been having difficulty with breakage of the part.

 

[46rob]

Here's another thought. This is a model I designed for FG--the Convair F2Y...it's a jet equipped with a seaplane hull and hydoskis. The engines are mounted over the wings, the skis are extended as the craft gains speed in the water
http://www.fiddlersgreen.net/AC/aircraft/Convair-SeaDart/Seadart.php
Perhaps you could incorporate some of the design features into your model.

Envision it with the wing turned 180 degrees.

I can send you the files for the model if you'd like to look them over.

 

[lizzienewell]

Rob,
Great tip on the Sea Dart. I've saved it in my notes. Yeah, that is what I'm thinking of for landing gear. I think I'll hold off on looking at your files. I'm not ready to tackle that challenge yet. I'm going to do a puffin based craft that will have bright red landing gear that resembles the feet of a puffin.
I could do the wings like the Flightship so that they are anhedral but turn up at the tips and put skis rather than floats at the wrists. Or maybe the wingtips can act as skis. No, if the ski is seperate and has knees it can raise the wings out of the water. Maybe I could think of the skis as thumbs
To take off the craft comes up to speed as a boat with the wings close. Then the thumb skis extend and it becomes a hydrofoil to lift the wings free. Hm the weird thing is that if the skis are on the wings and the wings are moving outward during takeoff the skis are going to be moving in v pattern. And that means that the skis need to be pointed at an angle instead of straight forward.

 

[46rob]

Some of the Sea Darts just had a single ski under the fuselage. --looked almost like a big surfboard bent into a "V" Your craft could start moving through the water, as speed increased the ski drops down, raising the hull. When ground effect is achieved it could retract again. Yours could be curved, with a pair of chines for stability to fit the contour of the underside of your craft.

I've always admired your work--I guess it's because I design jets, with lots of curves and angles. The moving parts, himnges and all are really slick. How big is your work?

 

[Jim Krauzlis]

Hey, hey, hey....turn away for a second and all of a sudden there's those funny looking craft with wings showing up around here!:grin:

Really an interesting little craft there, Lizzie...seems to be more of an aircraft than a boat though, isn't it? I would imagine you might have seen a larger reply from the sci fi folks if it was posted under that topic heading.

Very nice job of designing this little fellow, I admire your creative talent in doing so.

Thanks for sharing photos of this design and build with us.

Cheers!
Jim

 

[lizzienewell]

The fusalage is about 4" long and the wings extend to about 9".

I tried it in double this size but it just seemed to add complication by multiplying the number of pages. Right now the file is: 3 pages cardstock, 3 pages bond, 1 page disolvable foundation paper, 1 page diagram for wings, and one page transparency film. I like a low number of pages because I can see more of the parts at once and it takes less time to spray clearcoat and the like. I try to arrange parts on the page so that they make sense and can be cut quickly. I do multiple copies of the same part on the speciatly papers so that I don't have to print those pages everytime.
I'd hate to think how many pages it would have to be at double the size.
I like your idea for a ski. It's simpler than what I had in mind. The hull already has a scuff strip that is close in size and location to the central ski. I hardly have to change the design at all, just tell folks that the scuff strip is a ski.

 

[lizzienewell]

Rob,
Thanks so much for the idea and link to the "skis" on the Seadart. I've started designing them for my craft. Here is a picture of the gear so far. I haven't yet rebuilt the hull to accept it but I've photographed it next to where it will go. The ends of the hinge wires are still showing as well.
I haven't had much success with paper hinges so I make them out of wire and stripstyrene.

 

[lizzienewell]

Build #26 with the delta wings is done. I haven't been able to encorporate the ski yet. I've got Build #27 waiting for wings and #28 will have the ski landing gear. Hopeful build #28 will be the end, but then it probably won't. 30 is a nice round number.

 

[lizzienewell]

Here is another shot.

I promise next time I'll put it in the aircraft section.

 

[subnuke]

Bumped, for proprietary reasons, do not "Bump" old threads

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