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Royal

Smooth Operator

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This is just the shell of my idea. I did design it off of the line drawings of a long eze. Should be able to use the controls and linkages. Cabin is wider and lower. I also wanted to make it slippery as possible. I have more to and a bit of CFD tuning and probably some better airfoils after the CFD. 

Anyone can help or maybe build it if they like.

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Nice but swoopy  designs are hard to build.   Plugs, then molds, then structures—lots of work. There is already something similar by Revelation Aerospace And it does not seem like they are doing much.   
https://bobklynstra.wixsite.com/website

IMO, Your design is only practical as a model aircraft or a kit and the kit airplane market is very small.    It’s not a waste of time because you are developing an ability to design and draw things.    Make a flying model and see how it goes.    Good luck


-Kent
Cozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold

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I built a small glider first. Worked pretty good...till the dog jumped on it after the kids looked at it. Easily fixed though.

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But I also think with the foam cores that can be CNCed like the wings on burts planes this could easily be done on there. I have built plugs and molds for Anointed Aero and some other car projects. The pics are the plugs I made by hand then had them manufactured in fiberglass. 

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OIP (1).jfif OIP.jfif

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Posted (edited)

Your bumper-work looks great.  The problem with airplane design is that beautiful shapes must be drawn hand-in-hand with engineering data so I am interested in your calculations.  🙂

That's particularly important in a canard design.  I am not an engineer but I know that from from reading flight and accident reports.  For example Puffer found in the Cozy IV that a little too much canard area could drive the aircraft into wing-stall.   Perhaps your small canard will not develop enough lift at slower speeds to support the nose, or stall out at higher AOA before it can utilize the maximum lift of the wing.    You only know that by making preliminary calculations of centers-of-lift of the canard and wing and position of the center-of-gravity.    To do that, you have to know the position of the engine, the crewmembers, the fuel, and make a wag at the weight of the structure. 

Canard airplanes sit high off the ground so the airplane can rotate and land without hitting the prop.  The wheels have to be mounted at a station which will give the canard the leverage to lift the nose to rotate but if the wheels are too far forward, the ground handling will be tippy or the prop will hit the runway.  When we fly a Cozy solo, we have to add lead ballast to the nose to keep the CG in a good position (to keep the stall behavior acceptable).    Swept wings look cool but they are not necessary in subsonic airplanes.  Rutan only swept the EZ wings so he could mount rudders at the ends for stability and directional control.  There is just a lot to figure out.  I am not trying to be a debbie-downer, just bringing up things you may not have thought much about.

Justin has a simpler job by sticking pretty close to the original design where Rutan worked out those problems. 

Speaking of which:  Just saw this discussion of canard stall on HBA  https://www.homebuiltairplanes.com/forums/threads/canard-deep-stalling.33761/

Edited by Kent Ashton

-Kent
Cozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold

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I think I'll find an accurate 3d model of a Long-EZE and learn to use the CFD better.  I'll also go into learning how to do the engineering part of it. I did use real airfoils from NASAs airfoil plotter. What I had intended to do was design off existing aircraft and known drag reducing tricks and some not used but I have seen tested. Probably why the GLASAIRs are so damn expensive and look so good too. I think part of what makes a plane or company successful is the end user experience. People cant be cramped or have crappy interior. A 152 may have vacuum formed plastic interior and kinda suck but its an interior none the less and the airplane preforms amazing for what it is designed to do. I think I need to get back to why I want to design this plane and figure out if there is something that can help the swept front canard in CFD or not. I did change the wing tip airfoil but I didn't add any twist to it. I'll read more on the deep stall. 

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The X-29 had an interesting feature by the tail cone. It was like an elevator or some kind of flap to help the air come off the wing root. The AOA of the X-29 was insane. If they could figure out the wing flutter issue it would have been pretty amazing.

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Canard Pusher Leaflet No.76 has an article on deep stall.

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I did some digging. The Berkut 360 is pretty much what I was going after. They lowered the wing a bit. I'm guessing only to get the landing gear to be retractable. The engine stayed the same though which I would have thought they would want it inline with the wing. 

For the landing gear I don't see why they can't move them back so the angle to the propeller is better when it rotates as seen in the second picture. I also wonder about the 3 blade propellers vs the 2 as far as size goes.

I know there is the long nose mod for the long-ez. Is it in this side view of the long-ez?

 

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Oooer....

The side view you have there is the Berkut, not Long EZ.

You cannot move the mainwheels rearward. It would load the nose gear too much, and you would need excessive speed on the take-off run to lift the nose. I think there isn't much of an issue with prop-ground clearance in the Long EZ. Perhaps this is why the engine axis is above the wing level. As far as I know it is not recommended to fly off grass. 

The wing height in the Berkut looks pretty similar to that in the Long EZ. I think the Berkut gear leg pintle is in the fuselage, so wing height has little influence.

That Berkut picture raises a question. It looks like the engine axis is pitched upwards a tiny amount at the rear. Is that really the case?

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Ah sorry. The other screenshot didn't load. I lined up the propellers because I ASSUME that's where they are pretty much the same. And yes the wing didn't move much but I do wonder why they moved it down slightly. I need to upload the other drawing I did over them.

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I think you could change the front just slightly to make it look better and more like a jet or even just an add on to the top. Idk. Be fun to just make a scale model. I need to find pictures of all the bulkheads for the berkut 360 and the Long-EZ.

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3 hours ago, Royal said:

Ah sorry. The other screenshot didn't load. I lined up the propellers because I ASSUME that's where they are pretty much the same. And yes the wing didn't move much but I do wonder why they moved it down slightly. I need to upload the other drawing I did over them.

 

I think you have not yet downloaded the Open EZ plans. You should do this, and read up on the scaling issues on a few of the drawings. Also go to this site and get the build manual:- http://www.aryjglantz.com/p/documents.html  . Ary Glantz is one of the many heroes who have built the real thing from a lot of fairly uncoordinated data.

I would not scale anything from bitmap files unless you have some kind of scaling marks. The Long EZ plans have these, and I still think this is a primitive way to go. Some proper dimensions cannot be beaten. At least, if you use the plans that you can download from the Open EZ project, you also have station positions, waterlines, and buttock lines with definite numbers.

In my work/play with the Open EZ I have extended the nose. This is not because I think it looks nice. I thought the standard nose looked like it makes a downforce, and this is a bit absurd just ahead of a lifting canard. Someone else in the Long EZ forum posted a CFD pressure map that supports this hunch. 

I have played a little with the canopy geometry, and if I was building a real Open EZ I would use the UL390i engine. It has the same weight as the O-235, but for us in Europe, is more convenient to use than the old O-235, and with FADEC and fuel injection you can have a little more power, and unclutter the aircraft a little with no mixture or carb heat systems. Otherwise, I can't think how the basic Long EZ design could be improved. Anything else is a new aircraft. The EZ is a very clever, mouldless design.

I am unlikely to build a real EZ. I am in my 60s and need a simple kit like a Sonex. However, I like playing with the EZ in CAD, and intend to make one or two for X-Plane.

ez154.png

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I have made some the same observations with CFD and watching cars and planes in wind tunnel tests. I think just by changing the canopy and putting on a few fillets around the wings and canards you can reduce lots of drag even without doing any testing. Obviously this will change a lot of things with the plane. power needed. trimming during cruise. Landing speed. 

I think the best thing to do is build an RC model and put all the certain weights where they should be.  Doesn't even need to have a round shapely body as seen the the Cybertruck except for that huge red flat part. 

Then there is the lifting body that could be incorporated into a design but that starts making it hard to see over the edge.

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I started to digitally build the files. I think if most of the bulk heads are the same thickness you could make one sheet of 4x8 foam and fiberglass on one side. have the foam and all the other parts CNCed then vacuum form over top of the rest of the parts that need carved and cut. I think having a bulkhead kit for some people would save a ton of time. 

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