Will Electric Jet Ducted Fan Planes Be a Reality in Our Lifetime?

[violin_writer]

I have planed to make a small engine for my RC. I plane to use clay and (balsa layers) wood for structural support. I know clay is relatively heavy, so I only plan to use I tiny amount for the wind tunnel of the plane.

Like one other person had mention, I want to use a "cold" jet. I plan on spacing the fan blades apart and using a reverse nozzle to compress/focus the air and they use the rocket nozzle on the other side. Over all, air way should short.

What's even more wacky, is that I plan to do this with electric power... and I hope it will outlast all other Fan Duct planes. For electricity, I plan to use a combo of LiIon batts and Solar panels.

Am I far fetched? If you think not, then please help... I would like have some websites or something to look at. Thankyou:shy:

PS: I give you permission to laugh if you want.

 

[kach22i]

I don't think your ideas are wacky, I also have a concept for an "electric cold jet".

In lieu of clay please consider going to your local ACE Hardware store and spend some money on some West Systems Marine Epoxy, micro balloon fillers, graphite additives, fiberglass cloth and throw in some rigid insulation (extruded not bead board/expanded).

The above suggestion is a very expensive one, one you may do later for a larger scale or full sized project.

I think that you will find that bass wood and balsa wood are easily sculpted with course sand paper and razor blades (or small saws). Add some dope to seal it up and look like a pro.

I have not use automotive plastic body filler (Bondo) with wood, I don't think you will get a good bond, so don't bother.

 

[violin_writer]

Thanks--- how's your idea coming along.
You don't have tell me exactly what you did, I just want to know if you've made any process. Do you have a working model?

 

[kach22i]

Do you have a working model?

I have a hovercraft model project which is about 75% done, been that way for nine months just sitting until I have the time and money to fit it all together. Even at 1" = 1'-0" scale, I don't expect the 50 inch long model to prove or disprove any of the inlet air feed questions I have. Some things just don't "scale" right and I think this is one of those things.

 

[violin_writer]

I see... the root of all canceled or held experiments--- money.

Me I don't, and probably won't ever have the money to have a full scale model built (I'm terrified of heights so I'll probably never fly it). I am what you would call horribly poor. So, instead of having a $100,000 or so full-scale model, it'll be probably $200-300. I will work with what I can find without confrontation, anything to do with specific manufacturing of things. So, this plane with going to be hand made with everyday materials--- run of the mill DC motor.

I think the main problem with "cold" jet theory, is drag in the wind tunnel-- so, I think I'm going to come with a strange looking RC plane. Oh yeah, my engine system is neither "hot" nor "cold", I call it warm. I want to use 6v or 12v to heat a washer create heat at the end of the nozzle if possible.

I'm at 5% of my project. I know what materials to use, what engine. I just don't know how to configure that engine. I don't want to use two, but I do want to use 2 props.---- I'm starting to get a headache

 

[Cyrus]

I'm not sure what you mean by your explanation. For what it's worth, I'm currently building a wind tunnel model for this aircraft to be tested next week:

http://upload.wikimedia.org/wikipedia/en/f/f0/AD-150_10035.jpg

The model is made from Wind Tunnel Model foam in a CNC machine:

http://img12.imageshack.us/img12/410/pict0378gv3.jpg

http://img443.imageshack.us/img443/4131/pict0380sq9.jpg

http://img443.imageshack.us/img443/694/img0817cd2.jpg

You can very well make your own wind tunnel at home. I've done it using a leaf blower and plexiglass! The leaf blower will be loud as hell, but you will get a nice, fast, jet of air. Playing around with different configurations is fun, but make sure you have some references so that you can actually learn as you experiment. :)

 

[kach22i]

Cool an Osprey V22 like-ish UAV.

Awesome.

I've been told that if I want funding for any of my dream projects that I have to make it a UAV proposal.

I want those fans, how much?

Full circle, hey?
http://diydrones.com/photo/photo/show?id=705844%3APhoto%3A27287
http://api.ning.com/files/m8Up8XKxg7LZF1IiWSwstXmmaMj61sHuuspE7k7eEw4_/VTOL3.bmp

American Dynamics AD-150
http://www.americandynamics.us/News.shtml
http://www.americandynamics.us/i/i_b1001.jpg


E-Bay model Item number: 220353832572 ($138 static wood model)

 

[violin_writer]

I'm not sure what you mean by your explanation.

--- I read it over and I agree... lol! Never would have thought of that though, a wind tunnel with plexiglass and a leaf blower.

I didn't mean "wind tunnel", wind tunnel. sorry. I meant the duct around the fan. I think the "drag" or "lack of efficiency" comes from air intake. It's because the air is hitting the fan faster and faster as the plane increases speed; because the fan is getting air faster that it can suck-in. That's probably why the previous "cold jet models" haven't worked.
---But that is just me, I'm just 19, and haven't a clue in aeronautics.

By the way, that is one sweet plane! I wonder what the air intake on the bottom is for?
I like you're workspace too...:)

 

[violin_writer]

I'm not sure what you mean by your explanation.

--- I read it over and I agree... lol! Never would have thought of that though, a wind tunnel with plexiglass and a leaf blower.

I didn't mean "wind tunnel", wind tunnel. sorry. I meant the duct around the fan. I think the "drag" or "lack of efficiency" comes from air intake. It's because the air is hitting the fan faster and faster as the plane increases speed; because the fan is getting air faster that it can suck-in. That's probably why the previous "cold jet models" haven't worked.
---But that is just me, I'm just 19, and haven't a clue in aeronautics.

By the way, that is one sweet plane!
I like you're workspace too...:)

 

[aquitaine]

I have planed to make a small engine for my RC. I plane to use clay and (balsa layers) wood for structural support.

I would think making it out of plastic would be better, it will hold together better and (maybe) save some weight.

 

[Cyrus]

You are going to have a tough time getting plastic to come out lighter than balsa wood. I would not recommend it!

 

[violin_writer]

I did some reading... and decided to make a system of nozzles throughout the RC ducted fan system. I figured I would use a small intake, to vacuum in air at a high rate of speed. Then, I would create an internal nozzle, compress the vacuumed air by ramming it. The fan that vacuums the air would increase the air speed, the propeller would work just like a normal ducted fan by slowing it down and compressing it. Then, the compressed air would go out of the last nozzle just like a rocket.--- I'm not to confident about it because I'm the one who came up with it.

Could someone tell me what they thought?

F.Y.I.- It turns out I'm going to have some parts custom made so I'm going to have to use some plastic, wood, and then clay for insulation for the "heated nozzle" I'm also planning to use.

 

[Cyrus]

I would encourage you to make an engineering drawing.

 

[mheslep]

FSU all electric aircraft turbine propulsion w/ superconductors

Anybody familiar with the just released FSU electric turbo fan research by Masson and Luongo?

They believe they a design that competes on a physics basis with the the mighty icon of modern aviation, the gas turbine, though they're far off yet economically. My take is their essential contribution is to up the power density of the electric motor via a super conductor application from the usual 1kW/kg to as high as 20kW/kg. That compares to ~8kW/kg for the typical gas turbofan.

A major issue is the electric power source which would be the usual scramble for fuel cells, batteries, or even a combustion powered electric generator.

Electric 'jet' aviation would have several benefits:
-Engine itself would be over 95% efficient versus 60% typically for the turbofan
-Plenty of electric power (from whatever source) to run electric actuators instead of hydraulic
-With at least a partial hybrid battery system, recapturing some of the 16000 megajoules of Mgh energy of a large jumbo jet descending from cruising altitude becomes a consideration.
-Eventually the engines could be substantially lower weight than gas turbine comparables.
-Faster power up response.

Overview:
http://www.drives.co.uk/fullstory.asp?id=2033

In Applied Superconductivity, IEEE Transactions:
http://ieeexplore.ieee.org/search/srchabstract.jsp?arnumber=5153109&isnumber=5166701&punumber=77&k2dockey=5153109@ieeejrns&query=%28%28masson%29%3Cin%3Eau+%29&pos=5&access=no"

http://ieeexplore.ieee.org/search/srchabstract.jsp?arnumber=5067019&isnumber=5166701&punumber=77&k2dockey=5067019@ieeejrns&query=%28%28masson%29%3Cin%3Eau+%29&pos=6&access=no"

 

[Cyrus]

Anybody familiar with the just released FSU electric turbo fan research by Masson and Luongo?

They believe they a design that competes on a physics basis with the the mighty icon of modern aviation, the gas turbine, though they're far off yet economically. My take is their essential contribution is to up the power density of the electric motor via a super conductor application from the usual 1kW/kg to as high as 20kW/kg. That compares to ~8kW/kg for the typical gas turbofan.

A major issue is the electric power source which would be the usual scramble for fuel cells, batteries, or even a combustion powered electric generator.

Electric 'jet' aviation would have several benefits:
-Engine itself would be over 95% efficient versus 60% typically for the turbofan
-Plenty of electric power (from whatever source) to run electric actuators instead of hydraulic
-With at least a partial hybrid battery system, recapturing some of the 16000 megajoules of Mgh energy of a large jumbo jet descending from cruising altitude becomes a consideration.
-Eventually the engines could be substantially lower weight than gas turbine comparables.
-Faster power up response.

Overview:
http://www.drives.co.uk/fullstory.asp?id=2033

In Applied Superconductivity, IEEE Transactions:
http://ieeexplore.ieee.org/search/srchabstract.jsp?arnumber=5153109&isnumber=5166701&punumber=77&k2dockey=5153109@ieeejrns&query=%28%28masson%29%3Cin%3Eau+%29&pos=5&access=no"

http://ieeexplore.ieee.org/search/srchabstract.jsp?arnumber=5067019&isnumber=5166701&punumber=77&k2dockey=5067019@ieeejrns&query=%28%28masson%29%3Cin%3Eau+%29&pos=6&access=no"

I wouldn't call it an electric turbine, as it's not using any type of gas cycle. It's just an electric fan unit. This is a nice idea, but it's not getting off the ground until they find a power source: which is a fatal flaw.

 

[mheslep]

I wouldn't call it an electric turbine, as it's not using any type of gas cycle.It's just an electric fan unit.

You're right

This is a nice idea, but it's not getting off the ground until they find a power source: which is a fatal flaw.

Yes it is problematic, though I doubt fatal. The first IEEE paper points out the possible sources: traditional gas turbine electric generators, batteries, and fuel cells. The gas turbine generator would use traditional fuels, with the advantage (as the paper details) that there are significant aircraft design advantages in decoupling the propulsion source from the main energy conversion. Batteries and fuel cells are unsatisfactory at the moment only for 100% electric designs; a hybrid power source would still present major advantages: e.g. much quieter take-offs and landings, more efficient operation, etc. Even in an all battery or an all fuel cell design, the limitation is essentially only range (though that is drastically shorter for now, maybe 30x shorter.)

I believe, as the authors suggest, that the primary shortcoming of the concept at the moment is the economics of superconducting electric motors and associated cryogenics plant. Otherwise the advantages of electric ducted fans are such that I'd expect them to be already in use in niche aviation roles.

 

[mheslep]

Example all battery case

Regional jet like this Bombardier CRJ900.
http://www.aerospace-technology.com/projects/crj900/
Assumptions:
-Replace the entire max Jet-A fuel load of 11150 liters (9 tons) with batteries
-Battery energy density 0.2kWh/kg (about 55x worse than Jet-A)
-Replace 50% eff. gas turbo fan engines w/ 98% eff HTS electric fans

Gives me a maximum range of 150+ miles.

 

[Cyrus]

Example all battery case

Regional jet like this Bombardier CRJ900.
http://www.aerospace-technology.com/projects/crj900/
Assumptions:
-Replace the entire max Jet-A fuel load of 11150 liters (9 tons) with batteries
-Battery energy density 0.2kWh/kg (about 55x worse than Jet-A)
-Replace 50% eff. turbo fan engines w/ 98% eff electric turbo fans

Gives me a maximum range of 150+ miles.

If your numbers are right, that's terrible performance.

 

[mheslep]

Nuclear power case

Appears the old nuclear aviation case is feasible with HTS electric fans:
-737 fuel load = 26 tons
-737 engine power cruise (x2): http://en.wikipedia.org/wiki/Boeing_737" [24kN * 228m/s]
-Replace fuel load w/ Hyperion 25MW(e) small reactor. Weight, size: http://nextbigfuture.com/2008/09/ceo-of-hyperion-power-generation.html"

Range: Five years aloft

 

[Cyrus]

Nuclear power case

Appears the old nuclear aviation case is feasible with HTS electric fans:
-737 fuel load = 26 tons
-737 engine power cruise (x2): http://en.wikipedia.org/wiki/Boeing_737" [24kN * 228m/s]
-Replace fuel load w/ Hyperion 25MW(e) small reactor weight, size: 15-20 tons, 1.5M OD x 2M

Range: Five years aloft

Nuclear powered aircraft were seriously looked into by skunk works back in the 60s. The idea never got off the ground because the amount of lead shielding needed to protect the pilots was too heavy.

See: https://www.amazon.com/dp/0316743003/?tag=pfamazon01-20 for more good info on this.

 

[mheslep]

If your numbers are right, that's terrible performance.

Yes, certainly. Max range of that aircraft is normally 1720 miles. Though here's the key interest for battery power: assuming the HTS fans can be made cheaply, the battery powered aircraft is about the same cost per mile as the Jet-A powered one, including the battery cost, even at today's battery prices. Battery prices will go down, Jet-A will only go up.

 

[Cyrus]

Yes, certainly. Max range of that aircraft is normally 1720 miles. Though here's the key interest for battery power: assuming the HTS fans can be made cheaply, the battery powered aircraft is about the same cost per mile as the Jet-A powered one, including the battery cost, even at today's battery prices. Battery prices will go down, Jet-A will only go up.

An airplane that has a range of 150n.m. is an epic failure, no matter how cheap per mile it costs.

 

[mheslep]

An airplane that has a range of 150n.m. is an epic failure, no matter how cheap per mile it costs.

How do you measure failure? One can imagine the case that an for say, 20% lower operating costs an airline might use a similar plane to do nothing but make the shuttle run from NYC to Boston five times a day. And, it might offer be able to operate at night because of reduced noise, thus opening up time slots not available to traditional aircraft.

Realistically, I suppose that the costs of certifying a radically new technology aircraft for a small market segment make the 'electric shuttle to Boston' unaffordable.

 

[mheslep]

Nuclear powered aircraft were seriously looked into by skunk works back in the 60s. The idea never got off the ground because the amount of lead shielding needed to protect the pilots was too heavy.

See: https://www.amazon.com/dp/0316743003/?tag=pfamazon01-20 for more good info on this.

Thanks, I've seen some discussion, but are you sure this is a relevant source? I searched Skunk Works for 'nuclear', 'lead', 'shielding', and 'radiation': all the hits were about weapons.

 

[Cyrus]

Thanks, I've seen some discussion, but are you sure this is a relevant source? I searched Skunk Works for 'nuclear', 'lead', 'shielding', and 'radiation': all the hits were about weapons.

How did you search the book, do you have it in pdf format?

 

[Cyrus]

How do you measure failure? One can imagine the case that an for say, 20% lower operating costs an airline might use a similar plane to do nothing but make the shuttle run from NYC to Boston five times a day. And, it might offer be able to operate at night because of reduced noise, thus opening up time slots not available to traditional aircraft.

Realistically, I suppose that the costs of certifying a radically new technology aircraft for a small market segment make the 'electric shuttle to Boston' unaffordable.

You're taking an existing aircraft and reducing its range by an order of magnitude. That's always bad - really - really bad.

 

[mheslep]

How did you search the book, do you have it in pdf format?

online search at the Amazon link you provided, thanks again.

 

[mheslep]

You're taking an existing aircraft and reducing its range by an order of magnitude. That's always bad - really - really bad.

<shrug>. I'm talking the feasibility of turning a profit in aviation w/ electric aircraft.

 

[mheslep]

Regarding nuclear powered aviation, after reviewing some history I doubt the shielding would be major problem any more. A jumbo sized aircraft can afford to carry 10-15 tons of shielding. I expect the forever insurmountable problem is the risk of nuclear contamination in the event of a crash.

 

[Cyrus]

<shrug>. I'm talking the feasibility of turning a profit in aviation w/ electric aircraft.

You would have to do a cost benefit analysis to see if it's worth while to do such a thing.

 

[FredGarvin]

Look up "Project Pluto" for the nuclear propulsion R&D effort.

In terms of electrics, I think the idea will come in some form, some day. There are too many benefits to not chase after them. In part of my company's business, customers would go gaga at the chance for an extremely quiet ride. Of course, a ducted fan would have to be quite a bit larger in diameter to get the roughly the same amount of thrust.
There are hurdles that are on the scale of putting a man on Mars to overcome though. I always wince when I read a paper that the only benefit/output is a "model" to help in the conceptual design of something that can not exist at the current point in time.

 

[mheslep]

Thanks for the response Fred

...
In terms of electrics, ... Of course, a ducted fan would have to be quite a bit larger in diameter to get the roughly the same amount of thrust.

That was my first thought, but then I read that in today's http://en.wikipedia.org/wiki/File:Turbofan3_Unlabelled.gif" engines the majority of thrust already comes just from the bypass, i.e, the majority of propulsion comes from the low pressure compressor fan and not directly via the combustion gasses. Is that true?

Edit: found my source. The Luongo paper claims in existing turbo fans, the fan produces 85% of thrust, jet produces 15% of thrust. Example: GE90 has a BPR of 9:1

 

[FredGarvin]

You're right on that. The fan does produce the majority of the thrust.

 

[mheslep]

Overview of the basic propulsion concept from an earlier Masson, Luongo paper

A. Propulsion
In most modern airliners, propulsion is done through the combustion of jet fuel in turbofans in which, thrust is generated by both exhaust of hot gas and rotation of a large ducted fan generating an airflow bypassing the turbine. In modern engines, most of the thrust comes from the fan and only a fraction, less than 10%, comes form the exhaust. Therefore, it should be possible to replace the turbine by an electric motor and generate the full thrust using a large fan. This concept is presented in Fig. 4.

The duct and fan can be kept almost identical if an electric motor of the same shape and size as the original turbine is designed. The low rotation of the fan being limited to about 2,600 RPM, a propulsion motor will have to exhibit both high power density and high torque density. ...

Figure 14 shows the over all power system, in this case it is based on traditional gas turbines driving generators. A fuel cell system would replace the generator and gas turbine. I posit that a small battery supplement could have large advantages, though the authors don't address batteries. The key given the various new onboard boxes in fig 14 is low weight motors and generators. Superconductor tech. facilitates this, hence this research and the body of the paper.

 

[mheslep]

Powerpoint overview from the authors, better graphics.
http://www.masbret.com/asc08/ASC08_Tuesday_Plenary_Electric_Aircraft.ppt