I love this intriguing design and I trust your calculations on the trust capabilities are correct. Spinning that diameter barrel at 6000rpm on rollers will require precisely manufactured components built from exotic materials as compared with aluminum and Delrin rollers. Not to mention a lubrication strategy capable of dealing with the heat generated by 800 lbs of thrust @ 6000rpm. Bigger blades lower rpm is the only hope. But I hope I'm wrong because I love the thought.
You're right, this thing will eat itself at those loads. Just the side guide rollers being loaded with high surface speeds at high pressure and lots of sideways slip all under high dynamic loading via vibrations
Getting that thing properly balanced would do a lot for efficiency improvement, because it would lessen the loading on those guide bearings. Even in this prototype setup, having something like a bead roller stiffen that outer ring against deformation would allow for the other work that needs to be done.
A few suggestions. The inner spool which is connected to blades needs to be CNC machined and then balanced. Same for blades. The 2 sides of spool edges should not ride on the wheels as engine is losing a lot of energy on each bearing. That connection should be frictionless. Instead, the bearings should have a retractable mechanism which moves spool holding wheels, when the RPM of spool with bladed reaches certain threshold speed, and those wheels hold spool "parked" at low RPMs. For high RPM where motor generate thrust your spool should be avoiding any physical touching to other parts. You can employ the same technology of magnetic levitation (maglev) used on e-trains to hold spool in place on "magnetic rails" at the spool edges. Yes, it'll take extra energy but earlier this year Honeywell delivered tiny turbine driven generator for evtols that can be used to add energy to the main system in case of emergencies and for extended flights. Cheers from NY
Or, attempt to do something similar to what the Rolls Royce jet engines do with the shaft which runs up the centre of the engine, using air bearing tech. Place a cowel over the lip and make sure the outer rim and the inner surface of the cowel conforms to a certain shape with either side of the rim being the opposite to each other, then, air pressure alone should maintain the gap.
Cone in center to prevent the "slippage"? Coils were placed unevenly around the circumference and helped cause a lot of the shaking during the test. Need a little more rigidity perhaps. Amazing design, and even b4 it is perfected would make one hell of a sci fi prop. I really hope to see this concept grow!
Great going. Persistence is the way winners get there. Nice to see so many giving Peter encouragement. Subscribing is an excellent way of keeping abreast and not missing out on the further advancements and future news. Thanks Peter, you will make a difference.!!!
A great deal of work has been done on this design for subsea applications. Company call schilling robotics actually marketed rim driven thurster for subsea applications on their robots. I've also seen a subsea version of an inverted propeller for subsea alternative energy applications. Not sure if you're aware of these things are not, but I will try to find some references and put them in the comments later in the week.
theres a lot of remarks about maglev being used to make frictionless bearings . my thoughts were if he added small ducts to the inner ring it would force air in between the inner and outer rings making a pnewmatic bearing .
Something crazy? I had this idea in my head too! When I saw the movie Avatar 1 I was so intrigued by the SA-2 Samson aircraft. I thought about how a drive could look like in the future! And now YT gives me this video suggestion! Respect for your work! 😲👍
Wow, I must say that this design is simply amazing! The attention to detail is impressive and the overall look is very interesting. I love how everything flows together seamlessly. However, I was wondering if it would be possible to order and install two custom large thin bearings for a quieter and smoother performance. I believe this would take the design to the next level and improve its overall performance. Keep up the great work!
That is a great idea! I personally have been mulling over such a design (mostly for power generation) for about half a decade now, but so far everything is "rotating" only in my head ( as Tesla noted about his inventions ). Several venues for optimization points though. The entire structure can be considerably more deep and in such structure the blades clearly can be elongated ( and not so numerous ) starting very shallow at the front and getting deeper at the back, in such a way to create an empty cone in the middle where the fluid can self-organize. For more on the fluid dynamics and the misunderstanding of the Bernoulli physics phenomena (not a principle !) one can reed the post about "New Discoveries Regarding How Fluids (such as Wind and Water) Flow" by Dr. Robert D. Hunt, and consider the many implications it leads to especially when destining machines interacting with a moving fluid either for extracting of or for impacting on power.
Challenge remains on multiple bearing losses and outboard rub wheel configuration inherently increases failure points and high friction losses compared to 2 or 3 relatively small and easily cooled bearings in typical turbojet solution. If whole rotor could be floated on air or mag bearings maybe but then susceptible to shock loads and weight penalty.
it seems very energy efficient because of direct-drive advantage, but interesting would be a weight-energy-thrust comparison of similar sized conventional thrusters. also some stream and vortex analysis using smoke could give insight how this design behaves aerodynamically
Exciting technology. I hope it works out as desired. Humble opinion follows: Regarding the range of engineering considerations, I might include not just standard operating conditions, but foreseeable non-standard situations. Center ring might be good for multiple reasons, but especially adding strength and stability in case of indirect bird strike on airframe scattering debris toward the intake-side of the duct fan.
This is fascinating, but it also reminds of a boss who once worked for GE telling me about how the walls of the concrete bunkers they tested jet engines in were littered with impaled shrapnel from failures.
...just...AMAZING! Can't wait to see the plane...please don't stop on this...I really wanna see the plane. I realize there's quite a way to go so...good luck.
Simple math here. You have 16 bearings to facilitate hubless but if you had a hub you would live 2 bearings. 8x less friction. Love the creativity and certainly get a lot of points for skill in design and assembly.
Making a central shaft with relatively simple bearings would save a world of complexity while still allowing for the rim driven electric motor design. He could change the pitch of the blades from the center shaft like the pitch on a helicopter tail rotor. It looks cool as heck with a hole in the center, but cool looks are not a replacement for good old common sense.
@@mp6756 But isn't the center hole contributing to efficiency? Flow is being pulled through the center of the fan. If we place a hub there, thrust will likely decrease for the same RPM. On the other hand, the exposed blade tips at the center should be producing a lot of vortices. I think it would be wise to test the concept with and without a central hub, and let the numbers decide.
I would like to help you with this, I have a cnc lathe large enough to make a hydrodynamic bearing housing and rotor ring. that would definitively improve the efficiency. I find this project interesting, I actually have a home cnc machine shop with large industrial sized machines. lmk if there's something i can collaborate on with ya.
Outer dimensional hoops may help deflection. Two perfect-sized hoops to mount the leading and trailing edges of the outer shell. The strap could be eliminated, and the metal structure would make for easier bolt-in applications.
Please study magnetic brakes. Aluminum spinning inside a magnetic field is literally used to stop trains and stuff. This will NOT reduce drag, it will create whole another circle of hell to engineer around.
Another solution to rewiring fewer coils wye would have been putting coils in parallel (unless you already had them this way). You will be able to generate the same or lower kv with lower terminal resistance if you use more coils and stator coverage. IE, more torque capacity if controller and battery allows Very cool project!
Peter, I think this would be an interesting design for maritime propulsion in an azipod. If the blades are able to reverse, then the pod would only need 180 degrees of pivot.
if you connect the blades with some kind of ring in the center this might remove some of the vibrations, since the blades themselves are probably vibrating inside because they are not fixed
Very interesting aproach, personally i think looking into magnetic levitation bearing technology of electrical storage centrifuges could eliminate using guides at all and having near zero resistance as a good way forward All the best!!!
You probably alredy know about it but just in case you are like me and having a tentency of forgetting details like my brain does. From everyting that i learn so far with fan and turbine, having a way to link the inner end tip of the blade will reduce vibration also improving the balance of the fan ring will help. Adding a middle cone tip will also improve airflow. Else than that, this is a very interesting work. 👍Keep at it!
Cool project! I think you would need to reinforce where the rollers run. At high rpms, the blade will push hard outwards and as a blade moves between 2 rollers, it will deform the outer ring. So you need good support. Also, if you use large rollers, with many small bearings in each one, you might be able to handle the high rpms. Look forward to seeing where you go next!
I think what people were getting at concerning the inner on thr blades is reducing or eliminating drag caused by tip vortices and not blade flex. Also would this idea be able to be modified to work as ships propellers? Great idea.
Probably not as ship propellers, as even with the rim spinning, it's going to have drag under water, and massively increase the surface area of a moving part that doesn't actually provide thrust (compared to a stem that holds a traditional propeller). Not to mention if something gets sucked through there and gets caught on the blades, it's going to be a mess to get out, and cause more damage. There's also already something similar to this used in water propulsion, and that is water jet propulsion engines. Another thing about this design is it's not really a strong design for high torque, which is what is needed when pushing a lot of heavy water through a turbine in a stable manner. Water jet propulsion is pretty robust as is, with a solid central crank shaft that drives blades in a design that both sucks in water and also gives it a hard push on its way out, with two different rows of blade types. Keep in mind his design is primarily for low cost high volume for smaller craft. All it really does is invert the way an aircraft turbine is typically designed, where blades are fixed to a central shaft and rotate on it, while this rotates the blades from the outside with a hollow central shaft, which should also allow more unimpeded space for thrust to flow through. And it's really mainly designed to replace propeller driven planes, not jet engines.
This looks pretty good. In relation to the precision of the rotor, I wonder if a spin dryer tub would offer better precision for the next prototype - I see they spin at 3200 RPM from a quick google search. I realise there are many problems with this as a base, but off the top of my head, I can think of a couple of approaches to overcoming the short comings - mechanically hacking the tub to suit or using it to cast a rotor.. Probably a silly suggestion, but I'll take the scorn and ridicule if there is anything of value for you. :)
I saw the earlier video of your project, well done for getting this far. It seems to me you require more data before moving on. Smoke streamers would be an easy way of getting a good visualization of air-flow across the diameter. Others' ideas of an inner ring, joining the blade tips may become really valid if power increases were sort. The bending stresses would partly convert to more tolerable tensile stress and fundamental resonance issues, if they occurred would be well-damped. (get the Slo Mo Guys to do some high-speed analysis, I'm sure they'd love to! Or simply use strobe photography to at least see if resonant movement is occurring) I am surprised you were not able to filter the thrust output from the sensors; there are so many ways to achieve this. I love your original thinking!
6:18 maybe that isn't what they mean? Maybe their intent for the ring is to deal with wing tip vortices. I haven't done too much looking into this type of prop/fan but that's my guess.
I would suggest the inner ring would help with the balance problem. I also think a balance process like a bicycle wheel setup would be enough to check roundness and heavy spots.🚲
My question is: What's the idea behind the open center? Wouldn't you have enormous pressure loss and forward flow on that hole? One of the main challanges in commercial jet engine and industrial turbine design is to improve the tip seals to prevent pressure loss. Enginners use ingenious seal geometries and adjustable housing diameters to achive micron order gaps, but here there is a melon sized gap in the center. What's the idea here?
Once the flow starts moving there is an entrainment effect that pulls the air through the center. The blade tips at that point are not subject to tip vortices as the air is already moving past them. The entrainment is known for creating a much higher efficiency.
@@petermuller9177 Thanks for the reply! In absolute terms, of course air is rammed trough, but relative to the free stream, is the flow in the hole positive?
Your design is flirting w/ some very interesting things. Your variable position blades are creative. I personally am a simplicity advocate, but that's me. Anyway, your design already has the inherent geometry of a flywheel. It seems logical to take advantage of that. To manage the weight, one way would be make your rotating "rim" heavier. And make your blades/mounts out of Carbon fiber. There's some good videos re: 3D printed parts reinforced w/ Carbon fiber. Might be useful having magnetic gears to adjust low speed high-torque as it revs up. Keep it up, & Good Luck! :)
I'd maybe look at reducing the sharp corners on the leading/tailing tips of the blades and also possibly investigate making the rear edge less sharp. I would imagine both would be causing drag and acting to disrupt vortices produced in the airflow to the rear.
I had this design idea on paper 3 years ago but couldn't figure out how to hold it up during rotation ( I see wheels as rollers work). I am Happy to see someone with the same idea progressing.
The inlet needs to be ducted. One issue I see is the gyroscopic function causing control plane resistance. I designed a similar system for ships. A large horizontal wheel with coils and perimeter electromagnets to drive the screw through a 90 degree drive. The plus was the stabilization that came from the large spinning rotor. Not so good for an airplane. Figuring how to reduce your mass is crucial. Nice looking work.
Good effort on your coreless EDF design. Some brief observations to stop TH-cam deleting my comments again. Turbulence is caused by duct leading edge separation. For static test fit intake bell mouth. Figure 4a on page 26 of AMCA 210-16 shows typical dims. Out of balance could be handled by compliant mounts between duct ratchet straps and pallet. Put resonant frequency below problem rotational speed and critically damp. Might need a subframe between duct and pallet. Aluminium coil housings will suffer eddy currents that reduce B-field. Use machined nylon replacements or plasticine molded epoxy resin. Convinced there is more mileage in this prototype without too much spend.
It's definitely cool and interesting to look at while in motion very very very cool man hoping that you can power a plane with it it might not be the way to go but it's definitely awesome concept
This is brilliant!!! You freed Whirlwind!!! I have had such an idea for a long time, only it was not clear how to rotate it) !!! Thank you and good luck!!! 3d printing will help!
Nice toroidal engine. Can you fit a thruster in the middle? Thats right put an alternator on top of it and thatd be your base thrust and your pitch and roll would be the toroidal blade.
Peter you are doing great and I was following you since you started Raptor program. I want to say something about your blade and fan design. I think you need to modify your blade width. Your blade have same width throughout the length but if you make them more wider on outer ends you could get more thrust as there is big waste of space between fan outer ends. Regards
Awesome. 5:36 your FEA may be right in terms of not reaching deformation. But they are obviously flexing which will propagate a twist down to the ring. It would not harm and likely help to stabilize that be it with an internal ring or however.
This is definitely a cool idea, but there is a reason that turbines have blades attached to a central rotor, and that is stability of the blades under centrifugal force. So this will have speed and size limitations, but it certainly is cool to see someone actually try it
A few days ago i put 2 8 Blade Propellers on a high Speed drone motor. 3 Zoll Inch Diameter. It makes a little bit more than 1 hp. I see much more trust on my bicycle. 30.000 rpm
perhaps it would be an advantage if the individual blades could be made in the shape of shark fins; i.e. they should be longer at their fixed base than at their middle end.
I would agree the centrifugal force is negligible for the center ring, but perhaps it would help keep the rotor true to shape. As for balancing, have you tried balancing media? Little bb that by again centrifugal forces find their natural balancing point continuously.
I have some weights to balance it along with a balancing rig used for aircraft propellers but because the rotor is not true it's not possible to get a consistent reading on the balancer. Until you do you don't know for sure where to add the weight.
@Peter Muller balancer and fixed weights are sooo sooo tricky. They are not dynamic and self adjusting. So anything changes and it's off. 4 oz of airsoft bbs balances a whole tire and rim even after you pick up a rock or lose a chunk of rubber
A porpeler can not use balancing beads, but your rim shaped design could. I'm telling you dude, could be worth a think? $5 of beads, slight design change, no balancing required ever
Curious on anyones thoughts on the idea of having a rotor that's shaft mounted but still driven by the external ring. Imagining the center mounting is a minimal as possible.
I do, and offered it up to "Design the Future". A horizontal ring 50' in diameter weighing in at 12 tons. Electromagnets drive it, connected to a right angle gear box to the propeller shaft. The gyro force would help stabilize the ship in rough seas. I think what you describe is with higher merit than his current approach. It permits higher rpm without the huge tip mass increase.
are you using an inverter to change phase instead of mosfets for speed control? since the thrust will push toward back you should just have guides on the front side saving weight and drag. second, the rear rollers could use suspension. this might help with the circle being out of round. have you considered using polyurethane mounting blocks for the wheels? or bushings for existing bolts. i would go the inner ring or a wingtip for turbulence as well as strength inn the case of the inner ring.
You could add controllable pitch with a second ring and a second set of rollers that were attached to a point on the blades. That ring could be slid forward and back to give you controllable pitch of the blades. Just need a controller to map out your pitch curve across different rpm ranges for max efficiency. Sadly any more rpm will need precision machined parts and its going to get really expensive really fast.
That's exactly the first thing that I thought about. Thinking about how a variable geometry turbocharger works. A slewing ring or something of that nature to where the blade angles can be changed in real-time to get the maximum amount of thrust at any given Revolution what do an interesting consideration
Love your efforts: I hope you get a sponsor. $$$$needed . Check out the Induction drives on some CT scanners and their mercury-bearing or alt. Maglev-assisted floating braking inertia drives? Years of fascination ahead
Having an inner ring should dampen noise, help pull the outer ring more true during assembly, and provide strength against bird strikes .. may be just enough difference to make it back to the runway rather than the river ( some places don't have a river, its a shopping mall ) .. the heavier the blades the more substantial the outer ring must be to compensate for mass with harmonics continually trying to force outer ring to be out of round by small amounts creating a laundry list of bad things .. a center ring provides needed stability in many ways and can help keep the mass of the outer ring much lower .. is a win on so many fronts....
This thruster your building is more suited for water. For the lower RPMs and running in a tube that reduces from intake to exhaust. This motor is more suited for water jet like propulsion. The iffy part is in having electrical in water. Which means short circuits can happen easier.
This is awesome... But I have no use for it. However thinking about it if I could scale it down it's slightly make it run a bit silently, and put some creative style on this, I could have a jet engine fan with no apparent power source.
would love to see a wind tunnel-style test with this, I like that it has a lot less of the extra weight going around, any way to make it spin faster? rpm's? if you invert the blades could you have it spinning in both directions at the same time while pulling in the same direction? :D
Nice work! Some electric aircraft designs more than two 'engines' too... Just a thought. Obviously precision machining will make a subsequent prototype a lot smoother... You've done well with this by the sound of it, to get it running smoothly. I'm also beginning to get curious about how friction and noise might be refined even further at later stages... Maglev bearings? Not sure just another thought
Magnetic bearings would be great but they need to also absorb the thrust that is being generated by the rotor without the rotor colliding into the housing. Presently the delrin wheels are not showing any signs of getting hot or wearing. Most of the noise is coming from when the wheels come back into contact with the rotor each time. If the rotor was built with precision the wheels would never loose contact with the rotor. Then the main sound you would hear would be any noise from any of the bearings. They are not perfectly quiet by any means and the housing kind of acts like a speaker and amplifies any sound. Also, the coils being charged in one direction and then reversed also creates sound in much the same way that a speaker creates sound. It's still way quieter than a turbojet and even a piston engine exhaust.
@@petermuller9177 Oh right! Interesting. You obviously know what you're doing! Yes, in any case it's a lot quieter than a turbojet or piston driven turboprop. The design is inherently better than an open fan equivalent in this regard, as noise is contained and directed. I make note of this as conventional jet engine manufacturers apparently seem to moving in the direction of open fan designs... Which are inherently noisier and less safe. I see the potential for your design to be scaled up significantly. I'm not any kind of expert, but it's so much simpler and better than any other basic idea I've seen. I wish you good luck in developing it further! I hope it turns out how I think it might
@@petermuller9177 are you aware of the concept of a halbach array? en.wikipedia.org/wiki/Halbach_array by arranging magnets in a particular pattern, their magnetic moment can be displaced from one side of the array, so that the depth and strength of the magnetic moment increases on one side, while decreasing on the other, creating something that, for all intents and purposes, functions as a poor-man's monopole magnet. if you apply a series of them in key locations, it should allow you to use the entire rotor as a magnetic bearing, with some number of them on the leading and trailing edges to isolate lateral motion, and more sets around the ring to isolate the axial motion. you would need to calculate the collective force they would apply and make sure it is greater than the amount of thrust you expect to be generating, to prevent the thrust or wind-load from pushing the prop into the housing. once all of the arrays are in place and installed, you will need help, or a fitting machine of some sort, to insert the rotor, as the magnets will make it difficult, but once everything is set up, it ought to allow you to have a permanent floating connection between the two components, with absolutely no friction. couple that with the balancing beads someone else mentioned, and you would be able to get away with less precision on the machining of the housing rings, as you could have a millimeter or more of air-gap for your tolerances at that point. unfortunately, i do not know any of the math you would need, so i can do little more than direct you to the idea, as i am simply aware of the concepts involved and how they can fit together, but i do not know how to describe them mathematically. i hope this is able to help in some way.
Yes, I'm aware of what you're alluding to, I just did not want to have twice as many magnet brackets for this prototype and trying to get the rotor to float in the magnetic field was definitely beyond the scope of this first unit. Thanks.
I love this intriguing design and I trust your calculations on the trust capabilities are correct. Spinning that diameter barrel at 6000rpm on rollers will require precisely manufactured components built from exotic materials as compared with aluminum and Delrin rollers. Not to mention a lubrication strategy capable of dealing with the heat generated by 800 lbs of thrust @ 6000rpm. Bigger blades lower rpm is the only hope. But I hope I'm wrong because I love the thought.
I mean different materials and actively cooled bearings is definitely a possibility, that is what they they do in real jet engines after all
@bigmikeobama5314 Carbon fiber composites aren‘t very good for compression tho, so they prlly wouldn‘t be that good in these blades anyway
You're right, this thing will eat itself at those loads. Just the side guide rollers being loaded with high surface speeds at high pressure and lots of sideways slip all under high dynamic loading via vibrations
Getting that thing properly balanced would do a lot for efficiency improvement, because it would lessen the loading on those guide bearings. Even in this prototype setup, having something like a bead roller stiffen that outer ring against deformation would allow for the other work that needs to be done.
Brilliant! And the fact that you’re still striving to improve it shows you’re very professional determination.
A few suggestions. The inner spool which is connected to blades needs to be CNC machined and then balanced. Same for blades. The 2 sides of spool edges should not ride on the wheels as engine is losing a lot of energy on each bearing. That connection should be frictionless. Instead, the bearings should have a retractable mechanism which moves spool holding wheels, when the RPM of spool with bladed reaches certain threshold speed, and those wheels hold spool "parked" at low RPMs. For high RPM where motor generate thrust your spool should be avoiding any physical touching to other parts. You can employ the same technology of magnetic levitation (maglev) used on e-trains to hold spool in place on "magnetic rails" at the spool edges. Yes, it'll take extra energy but earlier this year Honeywell delivered tiny turbine driven generator for evtols that can be used to add energy to the main system in case of emergencies and for extended flights.
Cheers from NY
Also, for the above suggestion - the blades actuators should be fixed on the spool, powered by electromagnetic induction and operated via RF channel
liquid helium or nitrogen would be a little over kill for this
Or, attempt to do something similar to what the Rolls Royce jet engines do with the shaft which runs up the centre of the engine, using air bearing tech.
Place a cowel over the lip and make sure the outer rim and the inner surface of the cowel conforms to a certain shape with either side of the rim being the opposite to each other, then, air pressure alone should maintain the gap.
You should make a device like this and implement all your suggestions.
@@lastofthebest5102 I know a fair bit…access to the tools or the knowledge about how to use them on the other hand…no
Cone in center to prevent the "slippage"? Coils were placed unevenly around the circumference and helped cause a lot of the shaking during the test. Need a little more rigidity perhaps. Amazing design, and even b4 it is perfected would make one hell of a sci fi prop. I really hope to see this concept grow!
Great going. Persistence is the way winners get there. Nice to see so many giving Peter
encouragement. Subscribing is an excellent way of keeping abreast and not missing out on the further advancements and future news. Thanks Peter, you will make a difference.!!!
The thing I love about this most is the pursuit for knowledge. I think this is amazing.
Amazing, nice job do not stop, keep going
Been a minute since one of your vidoes came up for me. But I am glad your still at it. Glad your still passionate about this project.
I'd love to buy one of these as a novelty bedroom fan.
Well I for one am impressed that you thought of it and did the work to build it. Great.
Keep up the Research and incremental development brother. I’ve been thinking about this kind of internal bladed thruster for years.
A great deal of work has been done on this design for subsea applications. Company call schilling robotics actually marketed rim driven thurster for subsea applications on their robots. I've also seen a subsea version of an inverted propeller for subsea alternative energy applications.
Not sure if you're aware of these things are not, but I will try to find some references and put them in the comments later in the week.
Yes done decades ago at Harbor Branch Oceanographic Institute
theres a lot of remarks about maglev being used to make frictionless bearings .
my thoughts were if he added small ducts to the inner ring it would force air in between the inner and outer rings making a pnewmatic bearing .
Great work. Congrats!
Something crazy?
I had this idea in my head too! When I saw the movie Avatar 1 I was so intrigued by the SA-2 Samson aircraft.
I thought about how a drive could look like in the future!
And now YT gives me this video suggestion! Respect for your work! 😲👍
Wow, I must say that this design is simply amazing! The attention to detail is impressive and the overall look is very interesting. I love how everything flows together seamlessly. However, I was wondering if it would be possible to order and install two custom large thin bearings for a quieter and smoother performance. I believe this would take the design to the next level and improve its overall performance. Keep up the great work!
Long time no see.. Jolley good work man! Awesome 👌 👏 👍 😅
That is a great idea! I personally have been mulling over such a design (mostly for power generation) for about half a decade now, but so far everything is "rotating" only in my head ( as Tesla noted about his inventions ). Several venues for optimization points though. The entire structure can be considerably more deep and in such structure the blades clearly can be elongated ( and not so numerous ) starting very shallow at the front and getting deeper at the back, in such a way to create an empty cone in the middle where the fluid can self-organize. For more on the fluid dynamics and the misunderstanding of the Bernoulli physics phenomena (not a principle !) one can reed the post about "New Discoveries Regarding How Fluids (such as Wind and Water) Flow" by Dr. Robert D. Hunt, and consider the many implications it leads to especially when destining machines interacting with a moving fluid either for extracting of or for impacting on power.
Challenge remains on multiple bearing losses and outboard rub wheel configuration inherently increases failure points and high friction losses compared to 2 or 3 relatively small and easily cooled bearings in typical turbojet solution. If whole rotor could be floated on air or mag bearings maybe but then susceptible to shock loads and weight penalty.
it seems very energy efficient because of direct-drive advantage, but interesting would be a weight-energy-thrust comparison of similar sized conventional thrusters. also some stream and vortex analysis using smoke could give insight how this design behaves aerodynamically
Very cool update! I'm glad to see you're working out the kinks and figuring out the gremlins. 🍻 brother.
Exciting technology. I hope it works out as desired. Humble opinion follows: Regarding the range of engineering considerations, I might include not just standard operating conditions, but foreseeable non-standard situations. Center ring might be good for multiple reasons, but especially adding strength and stability in case of indirect bird strike on airframe scattering debris toward the intake-side of the duct fan.
This is fascinating, but it also reminds of a boss who once worked for GE telling me about how the walls of the concrete bunkers they tested jet engines in were littered with impaled shrapnel from failures.
...just...AMAZING! Can't wait to see the plane...please don't stop on this...I really wanna see the plane. I realize there's quite a way to go so...good luck.
Simple math here. You have 16 bearings to facilitate hubless but if you had a hub you would live 2 bearings. 8x less friction. Love the creativity and certainly get a lot of points for skill in design and assembly.
Making a central shaft with relatively simple bearings would save a world of complexity while still allowing for the rim driven electric motor design. He could change the pitch of the blades from the center shaft like the pitch on a helicopter tail rotor. It looks cool as heck with a hole in the center, but cool looks are not a replacement for good old common sense.
@@mp6756 like a fenstron
@@ahaffke Exactly that is a great example 👍
@@mp6756 But isn't the center hole contributing to efficiency? Flow is being pulled through the center of the fan. If we place a hub there, thrust will likely decrease for the same RPM.
On the other hand, the exposed blade tips at the center should be producing a lot of vortices. I think it would be wise to test the concept with and without a central hub, and let the numbers decide.
Balancing this would make great improvements.
This is fantastic, keep at it,
I would like to help you with this, I have a cnc lathe large enough to make a hydrodynamic bearing housing and rotor ring. that would definitively improve the efficiency. I find this project interesting, I actually have a home cnc machine shop with large industrial sized machines. lmk if there's something i can collaborate on with ya.
Outer dimensional hoops may help deflection. Two perfect-sized hoops to mount the leading and trailing edges of the outer shell. The strap could be eliminated, and the metal structure would make for easier bolt-in applications.
Need to look into magnetic levitation bearings.
This will reduce the noise and the bearing drag/losses.
It will also allow you to spin it faster
Please study magnetic brakes. Aluminum spinning inside a magnetic field is literally used to stop trains and stuff. This will NOT reduce drag, it will create whole another circle of hell to engineer around.
Another solution to rewiring fewer coils wye would have been putting coils in parallel (unless you already had them this way). You will be able to generate the same or lower kv with lower terminal resistance if you use more coils and stator coverage. IE, more torque capacity if controller and battery allows
Very cool project!
Peter, I think this would be an interesting design for maritime propulsion in an azipod. If the blades are able to reverse, then the pod would only need 180 degrees of pivot.
if you connect the blades with some kind of ring in the center this might remove some of the vibrations, since the blades themselves are probably vibrating inside because they are not fixed
Very interesting aproach, personally i think looking into magnetic levitation bearing technology of electrical storage centrifuges could eliminate using guides at all and having near zero resistance as a good way forward
All the best!!!
You probably alredy know about it but just in case you are like me and having a tentency of forgetting details like my brain does.
From everyting that i learn so far with fan and turbine, having a way to link the inner end tip of the blade will reduce vibration also improving the balance of the fan ring will help. Adding a middle cone tip will also improve airflow.
Else than that, this is a very interesting work. 👍Keep at it!
Cool project!
I think you would need to reinforce where the rollers run. At high rpms, the blade will push hard outwards and as a blade moves between 2 rollers, it will deform the outer ring. So you need good support.
Also, if you use large rollers, with many small bearings in each one, you might be able to handle the high rpms.
Look forward to seeing where you go next!
I think what people were getting at concerning the inner on thr blades is reducing or eliminating drag caused by tip vortices and not blade flex. Also would this idea be able to be modified to work as ships propellers? Great idea.
Probably not as ship propellers, as even with the rim spinning, it's going to have drag under water, and massively increase the surface area of a moving part that doesn't actually provide thrust (compared to a stem that holds a traditional propeller). Not to mention if something gets sucked through there and gets caught on the blades, it's going to be a mess to get out, and cause more damage. There's also already something similar to this used in water propulsion, and that is water jet propulsion engines. Another thing about this design is it's not really a strong design for high torque, which is what is needed when pushing a lot of heavy water through a turbine in a stable manner. Water jet propulsion is pretty robust as is, with a solid central crank shaft that drives blades in a design that both sucks in water and also gives it a hard push on its way out, with two different rows of blade types. Keep in mind his design is primarily for low cost high volume for smaller craft. All it really does is invert the way an aircraft turbine is typically designed, where blades are fixed to a central shaft and rotate on it, while this rotates the blades from the outside with a hollow central shaft, which should also allow more unimpeded space for thrust to flow through. And it's really mainly designed to replace propeller driven planes, not jet engines.
This looks pretty good.
In relation to the precision of the rotor, I wonder if a spin dryer tub would offer better precision for the next prototype - I see they spin at 3200 RPM from a quick google search.
I realise there are many problems with this as a base, but off the top of my head, I can think of a couple of approaches to overcoming the short comings - mechanically hacking the tub to suit or using it to cast a rotor..
Probably a silly suggestion, but I'll take the scorn and ridicule if there is anything of value for you. :)
This config as a bow-thruster, I'm making that one for sure! On a boat that is. (nowhere near the RPMs of corse)
the inner side of the blade may be running half speed but I assume their AOA is accordingly ( higher static AOA) , so still creating vortex.
I saw the earlier video of your project, well done for getting this far. It seems to me you require more data before moving on.
Smoke streamers would be an easy way of getting a good visualization of air-flow across the diameter.
Others' ideas of an inner ring, joining the blade tips may become really valid if power increases were sort. The bending stresses would partly convert to more tolerable tensile stress and fundamental resonance issues, if they occurred would be well-damped. (get the Slo Mo Guys to do some high-speed analysis, I'm sure they'd love to! Or simply use strobe photography to at least see if resonant movement is occurring) I am surprised you were not able to filter the thrust output from the sensors; there are so many ways to achieve this.
I love your original thinking!
So it's basically a really big 3 phase ac motor with no center axle? Very cool!
6:18 maybe that isn't what they mean? Maybe their intent for the ring is to deal with wing tip vortices. I haven't done too much looking into this type of prop/fan but that's my guess.
I would suggest the inner ring would help with the balance problem. I also think a balance process like a bicycle wheel setup would be enough to check roundness and heavy spots.🚲
My question is: What's the idea behind the open center? Wouldn't you have enormous pressure loss and forward flow on that hole? One of the main challanges in commercial jet engine and industrial turbine design is to improve the tip seals to prevent pressure loss. Enginners use ingenious seal geometries and adjustable housing diameters to achive micron order gaps, but here there is a melon sized gap in the center. What's the idea here?
Once the flow starts moving there is an entrainment effect that pulls the air through the center. The blade tips at that point are not subject to tip vortices as the air is already moving past them. The entrainment is known for creating a much higher efficiency.
@@petermuller9177 Thanks for the reply! In absolute terms, of course air is rammed trough, but relative to the free stream, is the flow in the hole positive?
Unbelievable....... I have been working on a similar design since this past January. Different but similar.
Your design is flirting w/ some very interesting things. Your variable position blades are creative. I personally am a simplicity advocate, but that's me. Anyway, your design already has the inherent geometry of a flywheel. It seems logical to take advantage of that. To manage the weight, one way would be make your rotating "rim" heavier. And make your blades/mounts out of Carbon fiber. There's some good videos re: 3D printed parts reinforced w/ Carbon fiber. Might be useful having magnetic gears to adjust low speed high-torque as it revs up. Keep it up, & Good Luck! :)
I'd maybe look at reducing the sharp corners on the leading/tailing tips of the blades and also possibly investigate making the rear edge less sharp.
I would imagine both would be causing drag and acting to disrupt vortices produced in the airflow to the rear.
I had this design idea on paper 3 years ago but couldn't figure out how to hold it up during rotation ( I see wheels as rollers work). I am Happy to see someone with the same idea progressing.
Great video
I'd like to see this in drones and other vtol craft awesome design
Cool concept!
Really interesting!
Having the suggested inner ring might help it survive a bird strike.
That blows! 🤣🤣🤣
Good build BTW, you've just got another subscriber.
Keep working on your idea!
The inlet needs to be ducted. One issue I see is the gyroscopic function causing control plane resistance. I designed a similar system for ships. A large horizontal wheel with coils and perimeter electromagnets to drive the screw through a 90 degree drive. The plus was the stabilization that came from the large spinning rotor. Not so good for an airplane. Figuring how to reduce your mass is crucial. Nice looking work.
It would be cool to see some smoke tests
This prototype is not running fast enough to provide any meaningful data from a smoke test.
Good effort on your coreless EDF design. Some brief observations to stop TH-cam deleting my comments again.
Turbulence is caused by duct leading edge separation. For static test fit intake bell mouth. Figure 4a on page 26 of AMCA 210-16 shows typical dims.
Out of balance could be handled by compliant mounts between duct ratchet straps and pallet. Put resonant frequency below problem rotational speed and critically damp. Might need a subframe between duct and pallet.
Aluminium coil housings will suffer eddy currents that reduce B-field. Use machined nylon replacements or plasticine molded epoxy resin.
Convinced there is more mileage in this prototype without too much spend.
www.amca.org/assets/resources/public/pdf/Education%20Modules/AMCA%20210-16.pdf
Hi Peter, any updates? Cheers!
It's definitely cool and interesting to look at while in motion very very very cool man hoping that you can power a plane with it it might not be the way to go but it's definitely awesome concept
awesome stuff
It's not inner ring but cone is definitely required, also the, shape of the blades need to be redesign, but it's a great idea..
Aeronautical Engineer here thinks you should add a variable pitch stator behind with a core entry cone, which should improve performance
This is brilliant!!! You freed Whirlwind!!! I have had such an idea for a long time, only it was not clear how to rotate it) !!! Thank you and good luck!!! 3d printing will help!
Nice toroidal engine. Can you fit a thruster in the middle? Thats right put an alternator on top of it and thatd be your base thrust and your pitch and roll would be the toroidal blade.
Great!!! Thank you!
Peter you are doing great and I was following you since you started Raptor program. I want to say something about your blade and fan design. I think you need to modify your blade width. Your blade have same width throughout the length but if you make them more wider on outer ends you could get more thrust as there is big waste of space between fan outer ends. Regards
Awesome. 5:36 your FEA may be right in terms of not reaching deformation. But they are obviously flexing which will propagate a twist down to the ring. It would not harm and likely help to stabilize that be it with an internal ring or however.
I like to think his neighbours can hear this thing like ''wtf is that damn noise'
This is definitely a cool idea, but there is a reason that turbines have blades attached to a central rotor, and that is stability of the blades under centrifugal force. So this will have speed and size limitations, but it certainly is cool to see someone actually try it
Could you use magnetic levitation for bearings?
A few days ago i put 2 8 Blade Propellers on a high Speed drone motor. 3 Zoll Inch Diameter. It makes a little bit more than 1 hp.
I see much more trust on my bicycle. 30.000 rpm
The reason one would include a inner ring is not, as you say, to prevent the blades from bending but to reduce turbulence at the blade tips.
perhaps it would be an advantage if the individual blades could be made in the shape of shark fins; i.e. they should be longer at their fixed base than at their middle end.
I would agree the centrifugal force is negligible for the center ring, but perhaps it would help keep the rotor true to shape. As for balancing, have you tried balancing media? Little bb that by again centrifugal forces find their natural balancing point continuously.
Google "tire balancing beads"
I have some weights to balance it along with a balancing rig used for aircraft propellers but because the rotor is not true it's not possible to get a consistent reading on the balancer. Until you do you don't know for sure where to add the weight.
@Peter Muller balancer and fixed weights are sooo sooo tricky. They are not dynamic and self adjusting. So anything changes and it's off. 4 oz of airsoft bbs balances a whole tire and rim even after you pick up a rock or lose a chunk of rubber
A porpeler can not use balancing beads, but your rim shaped design could. I'm telling you dude, could be worth a think? $5 of beads, slight design change, no balancing required ever
Litz wire may help? Maybe it is already there and I just missed the memo...
how much do the blades flex axialy due to thrust pressure? horizontal flex would be my concern for an inner ring
all I can think of, seeing this, is "ah, yes, the Human Blender."
Curious on anyones thoughts on the idea of having a rotor that's shaft mounted but still driven by the external ring. Imagining the center mounting is a minimal as possible.
I do, and offered it up to "Design the Future". A horizontal ring 50' in diameter weighing in at 12 tons. Electromagnets drive it, connected to a right angle gear box to the propeller shaft. The gyro force would help stabilize the ship in rough seas.
I think what you describe is with higher merit than his current approach. It permits higher rpm without the huge tip mass increase.
are you using an inverter to change phase instead of mosfets for speed control? since the thrust will push toward back you should just have guides on the front side saving weight and drag. second, the rear rollers could use suspension. this might help with the circle being out of round. have you considered using polyurethane mounting blocks for the wheels? or bushings for existing bolts.
i would go the inner ring or a wingtip for turbulence as well as strength inn the case of the inner ring.
I wonder how the new mobius/Sharrow Propeller would work in that configuration.
You could add controllable pitch with a second ring and a second set of rollers that were attached to a point on the blades. That ring could be slid forward and back to give you controllable pitch of the blades. Just need a controller to map out your pitch curve across different rpm ranges for max efficiency.
Sadly any more rpm will need precision machined parts and its going to get really expensive really fast.
That's exactly the first thing that I thought about. Thinking about how a variable geometry turbocharger works. A slewing ring or something of that nature to where the blade angles can be changed in real-time to get the maximum amount of thrust at any given Revolution what do an interesting consideration
Turbulence and other quick movements will be of highest mechanical challenge.
Love your efforts: I hope you get a sponsor. $$$$needed . Check out the Induction drives on some CT scanners and their mercury-bearing or alt. Maglev-assisted floating braking inertia drives?
Years of fascination ahead
Duxion eJet. Those guys might want someone like you on their team.
Having an inner ring should dampen noise, help pull the outer ring more true during assembly, and provide strength against bird strikes .. may be just enough difference to make it back to the runway rather than the river ( some places don't have a river, its a shopping mall ) .. the heavier the blades the more substantial the outer ring must be to compensate for mass with harmonics continually trying to force outer ring to be out of round by small amounts creating a laundry list of bad things .. a center ring provides needed stability in many ways and can help keep the mass of the outer ring much lower .. is a win on so many fronts....
I continue to struggle finding any advantage that is not wiped out my numerous [huge] disadvantages.
Awesome 👍
Perhaps magnetic bearings on the outer rims?
Very cool, keep posting on this! Can run some smoke so we could see the vortices
This thruster your building is more suited for water. For the lower RPMs and running in a tube that reduces from intake to exhaust. This motor is more suited for water jet like propulsion. The iffy part is in having electrical in water. Which means short circuits can happen easier.
Good stuff!
This is awesome... But I have no use for it. However thinking about it if I could scale it down it's slightly make it run a bit silently, and put some creative style on this, I could have a jet engine fan with no apparent power source.
would love to see a wind tunnel-style test with this, I like that it has a lot less of the extra weight going around, any way to make it spin faster? rpm's? if you invert the blades could you have it spinning in both directions at the same time while pulling in the same direction? :D
How does air flow look like when moving through the engine ?
Hi Peter im very interested in getting a few off these motors..pls inform
I've always wondered how a chain driven rim drive mechanism that would enable for oval mouths or really wide and narrow mouthed fans would work.
Nice work! Some electric aircraft designs more than two 'engines' too... Just a thought. Obviously precision machining will make a subsequent prototype a lot smoother... You've done well with this by the sound of it, to get it running smoothly. I'm also beginning to get curious about how friction and noise might be refined even further at later stages... Maglev bearings? Not sure just another thought
Magnetic bearings would be great but they need to also absorb the thrust that is being generated by the rotor without the rotor colliding into the housing. Presently the delrin wheels are not showing any signs of getting hot or wearing. Most of the noise is coming from when the wheels come back into contact with the rotor each time.
If the rotor was built with precision the wheels would never loose contact with the rotor. Then the main sound you would hear would be any noise from any of the bearings. They are not perfectly quiet by any means and the housing kind of acts like a speaker and amplifies any sound. Also, the coils being charged in one direction and then reversed also creates sound in much the same way that a speaker creates sound. It's still way quieter than a turbojet and even a piston engine exhaust.
@@petermuller9177 Oh right! Interesting. You obviously know what you're doing! Yes, in any case it's a lot quieter than a turbojet or piston driven turboprop. The design is inherently better than an open fan equivalent in this regard, as noise is contained and directed. I make note of this as conventional jet engine manufacturers apparently seem to moving in the direction of open fan designs... Which are inherently noisier and less safe. I see the potential for your design to be scaled up significantly. I'm not any kind of expert, but it's so much simpler and better than any other basic idea I've seen. I wish you good luck in developing it further! I hope it turns out how I think it might
I'm not sure that I know what I'm doing exactly. I'm just figuring it out as I go. :-)
@@petermuller9177 are you aware of the concept of a halbach array?
en.wikipedia.org/wiki/Halbach_array
by arranging magnets in a particular pattern, their magnetic moment can be displaced from one side of the array, so that the depth and strength of the magnetic moment increases on one side, while decreasing on the other, creating something that, for all intents and purposes, functions as a poor-man's monopole magnet.
if you apply a series of them in key locations, it should allow you to use the entire rotor as a magnetic bearing, with some number of them on the leading and trailing edges to isolate lateral motion, and more sets around the ring to isolate the axial motion.
you would need to calculate the collective force they would apply and make sure it is greater than the amount of thrust you expect to be generating, to prevent the thrust or wind-load from pushing the prop into the housing.
once all of the arrays are in place and installed, you will need help, or a fitting machine of some sort, to insert the rotor, as the magnets will make it difficult, but once everything is set up, it ought to allow you to have a permanent floating connection between the two components, with absolutely no friction.
couple that with the balancing beads someone else mentioned, and you would be able to get away with less precision on the machining of the housing rings, as you could have a millimeter or more of air-gap for your tolerances at that point.
unfortunately, i do not know any of the math you would need, so i can do little more than direct you to the idea, as i am simply aware of the concepts involved and how they can fit together, but i do not know how to describe them mathematically.
i hope this is able to help in some way.
Yes, I'm aware of what you're alluding to, I just did not want to have twice as many magnet brackets for this prototype and trying to get the rotor to float in the magnetic field was definitely beyond the scope of this first unit. Thanks.