Starman's plane

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Dan Thomas

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"Turbo-compounding was used on on several airplane engines after World War II, the Napier Nomad and the Wright R-3350 being examples. Turbo-compound versions of the Napier Deltic, Rolls-Royce Crecy, and Allison V-1710 were constructed but none was developed beyond the prototype stage. It was realized that in many cases the power produced by the simple turbine was approaching that of the enormously complex and maintenance-intensive piston engine to which it was attached. As a result, turbo-compound aero engines were soon supplanted by turboprop and turbojet engines." from wiki
Turbo-compounding is not the same as turbocharging. Not at all. Turbo-compounding uses an exhaust-driven turbine that is directly geared to the crankshaft and helps drive it. It doesn't compress air for the intake. And it was complex and heavy and pretty much obsolete when it showed up.


There are few piston engines of any sort that have flown above 40,000 feet. The reason jets can do it is that their true airspeed increases enormously with the reduced drag, and the ram recovery in the engine intake contributes a whole lot to the engine's compression. Piston engines aren't helped by that at all.

Dan
 

orion

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I've got Asperger's I understand thermodinamics as well as anyone, bar non. I am brilliant in thermodynamics the way that tesla was brilliant in electromagnetics and wave stuff. He could viualise stuff in his head so well that he could see how a machine wore and fix it before it was built. I'm not quite that good but I've already flown to 80,000ft in my head and it works just fine.
Thanks guys - I haven't laughed this hard for a while.

By this reasoning, if I visualized spending the night with Michelle Pfeiffer, that would be the same as actually doing it? I have a good imagination but that's not even close - I'm not convinced.
 

Topaz

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The real thing. I want to build a 70,000~80,000ft day triper.
Dreams are good. I don't think anyone would suggest you give up your dream.

However, you quite literally don't know what you don't know. The gulf between your 'want' and what you actually have the knowledge to achieve right now is so vast that I can't even put it into words.

You do yourself a huge disservice with statements like, "I've flown 80,000ft in my head and it worked fine." That's fantasy land. It bears little or no relation to reality, and no, it won't tell you what will work or not. Someone with the necessary experience and training might be able to visualize some of the problems, but they would do so as a means to frame the right means of putting real-world engineering to them. Dreaming is not problem-solving or engineering, and never will be.

Pie_row, you've built your air-castle. Now's the time to put real foundations under it. Fantasy like you've shown here today will just keep you from ever actually making your dream come true.
 

Starman

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thanks, I didn't mind the discussion.

Does this forum have a thread splitter?

I gotta admit I've been quite amused to see the direction of your thoughts and the evolution of your configuration - it reminds me of a project I did some time back for the purpose of coming up with a versatile airframe capable of utilizing numerous engines with only minimal modification. The initial configuration was a flying wing very similar to the configuration you've been approaching but, given the need for a variety of engines and a very large cockpit (for scale, the cockpit on the tandem was about the same size and volume as that of an F-14), I had to add booms and a horizontal. The picture is at: Arrow aircraft description
Yes I remember seeing that but hadn't noticed the V8 power till now.

The cockpit on my design is pretty compact, except for width (28-30") it is low and reclining, like a Sailplane or a VariEze. The fuselage is also as compact as possible, see side views.

I think this sort of reverse delta or low AR Fauvel style plank is the most efficient package which includes a horizontal tail surface with a flying wing.

wing loading - 10 psf
wing area - 210 sq.ft
span - 30 ft
length - 20.5 ft nose to prop
 

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JimCovington

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thanks, I didn't mind the discussion.

Does this forum have a thread splitter?



Yes I remember seeing that but hadn't noticed the V8 power till now.

The cockpit on my design is pretty compact, except for width (28-30") it is low and reclining, like a Sailplane or a VariEze. The fuselage is also as compact as possible, see side views.

I think this sort of reverse delta or low AR Fauvel style plank is the most efficient package includes a horitzontal tail surface with a flying wing.

10 psf - 210 sq.ft. - 30 ft span - 20.5 ft. length, nose to prop
Interesting! The spindly forward-retracting gear reminds me of the Lesher Teal.

http://www.homebuiltairplanes.com/forums/design-structures-cutting-edge-technology/4393-lesher-teal.html
 

Starman

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The reason is because that design is a canard with high lift bias to the front. For me this planform is the most efficient in terms of overall lift versus combined wing area for more short coupled designs, this wouldn't apply to designs with really long tails. When you add the horizontal tail area to the wing on short coupled designs it adds a lot of total wing surface, you end up with hardly any less than a lower wing loading tailless plank or delta would require for a given stall speed and you have the added surfaces to make and sometimes more interference drag.

For now I prefer my plank version but the problem with both it and the delta is the sheer size of the pieces (I want a 50 - 55 mph stall speed) and the army of boys or cranes it would take to move them.

I always liked the idea of a bird shaped plane, and this plank has that, I saw a crow flying ... like the wing. I feed a few of the local crows and we are getting to be buddies.

The canard or tandem wing version has the smallest and most manageable piece size.

As far as canards go, it's only logical to want to want the hard working front wing to carry most of the weight to make for the smallest overall wing area, kind of like quicky style rather than varieze style, but with even more weight bias to the front.

The interesting thing is that by doing this and pushing the line as far as short coupling is concerned (tandem wing is ideal for short coupling), you get the front wing flap/pitch control surface actually behind the CG :D try to wrap your mind around how that affects control and stability and I'll get back to you later :roll:

+ the rear wing control surfaces will not be just ailerons but be elevons, interlinked with the front elevators like the variviggen and some other tandems have used.
 
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Starman

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These are 30, 40, and 50ft spans of about 210sq.ft, not counting the elevators. One of the things I like about the Fauvel style is how easy it is to switch aspects ratios and range and how streamlined they are.

Getting back to the compactness of the fuselage, since it has a long nosecone the front bulkhead to prop length is about 16 3/4 ft long, overall length is 26 ft. Do you think the vortex from the strake will cause an elevator problem at high AOA? I think it might affect it a little but it won't be too bad.
 

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Autodidact

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For some reason I like the long span version, reminds me of a soaring bird or even a Pteradactyl.
 

Starman

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It turns out that if you make the span short enough, with the wing area big enough, and the engine and prop far enough forward, that you can have a delta wing and still incorporate the power steering, or as you chaps call it, thrust vectoring, into the design. I guess I'll stick with the delta plan after all. The neat thing is that having thrust vectoring will make it easy to do the cobra maneuver, something that I though would be fun earlier. :) 24 foot span, 210 sq.ft.


 

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Starman

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This final sketch looks very nice, any progress on this in the last 3 years?
Hi Dirk, the design migrated on to other things. I always liked the rear engine for visibility but a front prop is much better for many other efficiencies so my last design is a mid engine front prop plane that looks pretty standard. I don't know if this pic will take, but the last design was posted in the 'Night Fury' thread. This is a side view but the location of the prop in that particular drawing is just one crazy idea. The primary location is at the nose where you see a spinner like object =) It's the side view in post #16 in the Night Fury thread.

http://www.homebuiltairplanes.com/forums/aircraft-design-aerodynamics-new-technology/9104-night-fury-2.html
 
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Starman

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Not sure if you'll get an answer... he hasn't checked in on the forum for over a year.

Hi Bruce, I had a change of plans. My political views changed to 'run for the hills' so i sold the corvette aluminum V8 and a bunch of other stuff and ended up in the remote mountain wilderness in the South of Ecuador, living on a little farm which is a bit of a walk upriver from the nearest town, which is a teeny little town.

I am curious about ultralight rules in Ecuador, but not in a hurry to find out.
 
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