These style fans were a pretty popular project years ago in the 3D printing community. Most of them just used computer fans, which I very much doubt had the airflow and static pressure needed to make the "air multiplier" design work very well. It was fun seeing you revisit this idea with a fan design that could probably deliver the airflow needed for something like this.
they certainly dont have the needed pressure to produce that effect, but with a large enough fan they work pretty well. I used a Fractal Dynamic GP18 180mm fan that has 261m³/h airflow and 2.26mm H2O at max speed (1200RPM at 12V but i run it at 20V so its way more) while staying pretty low noise. Its been running 12 hours a day for the past 2 weeks.
Yes, I'm trying to do it as well. But my version is a true bladeless fan in that the air is taken in from the back and passed back to the front which should give it x2 the air flow needed. Still working out air area. (Edit): Yes, you need to calculate the area of the fan and convert that same area throughout the outflow. You here have cut the area by 95%~ giving the bladeless fan itself only 5%~~ of the fan. There is also a LOT more math needed. But just remember to keep the area of the airflow the same from start to finish.
@@mach10point4 Yes, was thinking about that. It was created in FreeCAD and I think CZcams hates links? But after coffee we can figure out a way of contact. :)
@@mach10point4 I gave up on it like 2 years ago and been thinking of looking at it again. The main issue is that I had the math wrong and could not get even air flow ---mostly due to the limitations of...FreeCAD. :)
I'm no expert on fluid dynamics, but my first thought would be to ditch the axial flow fan and go for a blower style fan and just focus on trying to make it more quiet. Cool project! Keep up the nice work!
You should try incorporate the "bladeless fan" Into a jet engine system. Without so many compressor turbines in the way of direct airflow, i assume that there would be less drag and more room for combustion space.
Never thought about this before. I think it would be hard to scale this to produce pressures required for combustion, whereas for fans you can just add more stages/blades. I’ll look more into it, thanks
Hi, you do not need to hint that this is Dyson IP and worry about infringement. You are making an "air multiplier" - google that and you'll find loads of products, designs, and scholarly papers on the underlying physics. Dyson does NOT own the wide world of air multiplier technology. I have designed and 3d printed air multiplier nozzles for compressed air systems and they absolutely work, if you get the parameters right. From looking at what you've got there, I would say your whole nozzle is way too big for the fan you're using. Try making at about 1/3 scale and make the gap between inner and outer as small as you physically can with your printer, without them getting fused together. You might need to use a 0.2mm nozzle. The reason is that air multipliers trade velocity for volume. If you want a lot of volume you need a lot of air velocity from the source. The tighter the channel air must flow through, the faster it will go. So super tight gap = super high volume. I didn't figure that out until about the 7th or 8th revision of my nozzle design. Another (hopefully)-helpful hint, don't print it on its side. Cut the model annularly in two parts, print upright, then superglue the inner part into the outer part. Please note, not sure what your intended purpose is for this, but unless it's inflating trash bags, an air multiplier doesn't do what you might think it's supposed to. Again, I didn't figure that out until very late in my design process, once I had made something that actually worked. If you're expecting a more powerful jet of air, forget about it. A powerful jet is made from high speed, high pressure air. Speed and pressure are the two things that you *LOSE* with an air multiplier. Speed and pressure are the two things that you trade for increased volume of air. So, you can use an air multiplier to inflate a trash bag in a fraction of the time, or to more effectively evacuate fumes from a room, but if you're expecting a more satisfying blast of air from a desk fan, this ain't that. In my case I was better off just using a straight pipe for a nozzle rather than an air multiplier.
This a cool project i wouldnt worry about i.p. theft or whatever your not big enough yet. Dont be afraid or restrict yourself like that ask permission later unless youre gonna produce stuff. I say run with it, take the time and entertain us. maybe easier a little bigger/different material. I want a mini Jon fan lol
I'd look into blower fans. Despite being known for being noisy(like a turbo), they build up a heck of a lot of static pressure.
These style fans were a pretty popular project years ago in the 3D printing community. Most of them just used computer fans, which I very much doubt had the airflow and static pressure needed to make the "air multiplier" design work very well. It was fun seeing you revisit this idea with a fan design that could probably deliver the airflow needed for something like this.
they certainly dont have the needed pressure to produce that effect, but with a large enough fan they work pretty well. I used a Fractal Dynamic GP18 180mm fan that has 261m³/h airflow and 2.26mm H2O at max speed (1200RPM at 12V but i run it at 20V so its way more) while staying pretty low noise. Its been running 12 hours a day for the past 2 weeks.
Yes, I'm trying to do it as well. But my version is a true bladeless fan in that the air is taken in from the back and passed back to the front which should give it x2 the air flow needed. Still working out air area. (Edit): Yes, you need to calculate the area of the fan and convert that same area throughout the outflow. You here have cut the area by 95%~ giving the bladeless fan itself only 5%~~ of the fan. There is also a LOT more math needed. But just remember to keep the area of the airflow the same from start to finish.
Interested in seeing what this looks like, if possible
@@mach10point4 Yes, was thinking about that. It was created in FreeCAD and I think CZcams hates links? But after coffee we can figure out a way of contact. :)
@@mach10point4 I gave up on it like 2 years ago and been thinking of looking at it again. The main issue is that I had the math wrong and could not get even air flow ---mostly due to the limitations of...FreeCAD. :)
I'm no expert on fluid dynamics, but my first thought would be to ditch the axial flow fan and go for a blower style fan and just focus on trying to make it more quiet. Cool project! Keep up the nice work!
Yeah that's a great point. I was using the fan I had on hand but that was more designed for a thrust generating application cause I was lazy. Thanks!
You should try incorporate the "bladeless fan" Into a jet engine system. Without so many compressor turbines in the way of direct airflow, i assume that there would be less drag and more room for combustion space.
Never thought about this before. I think it would be hard to scale this to produce pressures required for combustion, whereas for fans you can just add more stages/blades. I’ll look more into it, thanks
Hi, you do not need to hint that this is Dyson IP and worry about infringement. You are making an "air multiplier" - google that and you'll find loads of products, designs, and scholarly papers on the underlying physics. Dyson does NOT own the wide world of air multiplier technology.
I have designed and 3d printed air multiplier nozzles for compressed air systems and they absolutely work, if you get the parameters right. From looking at what you've got there, I would say your whole nozzle is way too big for the fan you're using. Try making at about 1/3 scale and make the gap between inner and outer as small as you physically can with your printer, without them getting fused together. You might need to use a 0.2mm nozzle. The reason is that air multipliers trade velocity for volume. If you want a lot of volume you need a lot of air velocity from the source. The tighter the channel air must flow through, the faster it will go. So super tight gap = super high volume. I didn't figure that out until about the 7th or 8th revision of my nozzle design.
Another (hopefully)-helpful hint, don't print it on its side. Cut the model annularly in two parts, print upright, then superglue the inner part into the outer part.
Please note, not sure what your intended purpose is for this, but unless it's inflating trash bags, an air multiplier doesn't do what you might think it's supposed to. Again, I didn't figure that out until very late in my design process, once I had made something that actually worked. If you're expecting a more powerful jet of air, forget about it. A powerful jet is made from high speed, high pressure air. Speed and pressure are the two things that you *LOSE* with an air multiplier. Speed and pressure are the two things that you trade for increased volume of air. So, you can use an air multiplier to inflate a trash bag in a fraction of the time, or to more effectively evacuate fumes from a room, but if you're expecting a more satisfying blast of air from a desk fan, this ain't that. In my case I was better off just using a straight pipe for a nozzle rather than an air multiplier.
This a cool project i wouldnt worry about i.p. theft or whatever your not big enough yet. Dont be afraid or restrict yourself like that ask permission later unless youre gonna produce stuff. I say run with it, take the time and entertain us. maybe easier a little bigger/different material. I want a mini Jon fan lol