3d printed mini horizontal wind turbine

[esposcar]

This wind turbine have a special blade design that makes the device more efficient. It uses 2 small DC motors and it is able to generate between 10-20 watts under strong winds.

[MagnetJuice]

Hi esposcar, welcome to Fieldlines.

Interesting blade design, what is the function of the v-funnels in those blades?

Ed

[esposcar]

The blades shape uses the Venturi effect which is a jet effect; as with a funnel the velocity of the fluid increases as the cross sectional area decreases. The main purpose effect is that the tighter part of the V shape is faced in opposite direction of the blade spin direction, therefore collecting all the air on the widest part of the V shape and as the air slides down the V and get more narrow, the air will slide faster giving more impulse to the blade itself and finally the air will exit pushing even faster the blade. It will have more torque compared to a flat blade. But I would love to have objective opinions or sensations of the people here that like to build their own wind turbines. I let some visual images that explain how it would work this blade configuration.

I wanted to post a link for anybody that have a 3d printer to print this prototype for free of course but I am new and do not have enough privileges to post links. In any case if it is typed in google //HORIZONTAL PORTABLE 3D PRINTED WIND TURBINE cults 3d// you find it in the first line result.

[MagnetJuice]

Hi Oscar,

I did a search with the terms suggested and found a lot of information about Oscar Garcia and Ali El Zaher Buendia.

I found a few Kickstarter Campaigns to raise funds.

I found these unbelievable claims:

"Check out all the details of the new wind turbine that generates up to 100 MW of clean energy. Wind energy equipment can be printed or even handcrafted.
The inventors Ali El Zaher Buendia and Oscar Garcia are revolutionizing the wind energy industry with a new equipment that has a unique design. It is a vertical wind turbine that is printable on a 3D printer. The duo recently announced their project, called the Bi-Generator Vertical Wind Turbine, which has the potential to generate up to 100 MW of power.

The clean energy turbine can be installed on top of houses, terraces or buildings and can even be configured as an array to meet all user demands regarding domestic energy"

I have seen many other ‘inventors’ claiming that they are revolutionizing the wind energy industry. Maybe you will be the first to succeed?

The small DC motor recommended for this turbine has no specifications except for size, weight, RPM and shaft size.

32mm diameter, 50 grams, 12v at 5600 RPM, 2mm shaft.

How many thousands of those tiny motors do we need configured as an array to meet all user demands regarding domestic energy?

Also, how long those 3D printed small gears will last, spinning at 5600 RPM?

Oscar, what is your ultimate goal once you get the money from all the Kickstarter Campaigns?

Ed

[esposcar]

The small DC motor goes in the range of micro wind turbines so you should compare it with its niche not with bigger devices (regarding domestic demands obviously you will need hundreds to cover the electric need of a house, obviously, but I never talked about this device doing it). I keep myself humble and I have no control over what others write about me. I try to innovate and make things different. By the way, the gears will resist 5600 rpm and more just if they are made with the right materials. If you want it for years, then you can print it with carbon filaments or silk but there are plenty of other materials that can do the work. Please have in consideration that are materials done for mechanical applications. 

The motor specifications can be found if it is written in google Uxcell RF500TB-12560 DC5V-12V 2300RPM-5600RPM no load speed 32mm diameter DC motor or equivalent. It can use a more strong DC motor with another replacement but it fits perfectly under this micro range turbine.

About the claims that you mentioned (the article does not talk about this prototype that I have posted here, there are other prototypes that uses other dc motor sizes and uses much bigger DC motors that with enough wind and as it is configured to have extendable turbines, physically it can reach a decent number of watts. One of the features of prototypes (big ones) is that they are totally configurable to hold any kind of generator (under a limit of course) and the turbines have extendable pieces in order to increase the diameter if there are 2 or 4 generators working in the same prototype for example.

I succeeded in my last kickstarter campaign (2 years ago) and I delivered the rewards and backers liked the devices, my goal is to continue to innovate prototypes and I have much more in mind. And in this next campaign I am delivering counter rotation VAWT and HAWT devices using dc motors from 50 watts up to 350 watts and of course the diameter of the turbines have to be appropriate for this request. My objective in kickstarter is to be able to fully dedicate myself to innovate and money as you say, what I will do with it, is to build the prototypes and sell them, in this case as rewards. The last campaign I rebuilt all the prototypes to improve them after the campaign ended and I even wasted more money than what was achieved for materials, machine etc but I do not care because I like what I do.

One of the prototypes of the last campaign was used by a group of students from the Munich Applied Science University for their end of the year project and in the link below you have their pdf work written in German, but it was an honor for me. It is attached as Projektarbeit.

I will enclose here some pictures of some of the prototypes from the last campaign and what comes in this next campaign, I do not want to do spam, but I am in the obligation to defend myself

[esposcar]

As I am restricted for posting links, here you have in a screen shot a number of 19.50 Amp that show the multimeter of one of the prototypes that the article was talking about but it was an indoor test dine with a leaf blower, but anyway under strong winds and up in a high roof, that would be a very decent amount. The pity is that the voltage including the volts did not show at the same time for total watts purpose as I was using just one multimeter. But you can view also the speed of the turbines. Anyway, to be fair that measure of amps was not normal, so maybe there was a mistake of the multimeter but also could be perfectly possible as  the leaf blower was close to the turbines.

I attach another screen capture of another video that show the micro horizontal wind turbine of this post using just one DC motor.

[JW]

 TEST links

https://www.electrical4u.com/watts-law/

[Adriaan Kragten]

Any activity performed on vertical axis wind turbines based on the difference in between the aerodynamic drag coefficient of hollow and convex bodies is a waste of time and money. Study my free public report KD 416 in which I prove that the maximum Cp of pure drag machines is only about 0.05 and that the optimum tip speed ratio is only about 0.15 (see figure 2 given in KD 416). A well designed horizontal axis wind turbine with a good airfoil can have a maximum Cp of at least 0.4 at a design tip speed ratio in between 3 and 8 and uses much less material for a certain swept area (see chapter 4.3 of my free public report KD 35).

A Savonious rotor is much better than a pure drag machine because it can have a maximum Cp of about 0.22 at an optimum tip speed ratio of about 0.9 (see free public report KD 599). This is because a Savonious rotor works partly on drag but also partly on lift as it is designed with overlapping buckets which allows a flow through the rotor. But a Savonious rotor uses much and much more material for a certain swept area than a well designed horizontal axis wind turbine and therefore it has very high investment costs per generated kWh if it is used for generation of electricity.

[Adriaan Kragten]

The blades shape uses the Venturi effect which is a jet effect; as with a funnel the velocity of the fluid increases as the cross sectional area decreases. The main purpose effect is that the tighter part of the V shape is faced in opposite direction of the blade spin direction, therefore collecting all the air on the widest part of the V shape and as the air slides down the V and get more narrow, the air will slide faster giving more impulse to the blade itself and finally the air will exit pushing even faster the blade. It will have more torque compared to a flat blade. But I would love to have objective opinions or sensations of the people here that like to build their own wind turbines. I let some visual images that explain how it would work this blade configuration.

I wanted to post a link for anybody that have a 3d printer to print this prototype for free of course but I am new and do not have enough privileges to post links. In any case if it is typed in google //HORIZONTAL PORTABLE 3D PRINTED WIND TURBINE cults 3d// you find it in the first line result.

Nice story but I am afraid that this won't work for three reasons. The first reason is that the law of Bernoulli is only valid for a tube. The funnel which you have created is open at one side so instead of flowing in the direction of the smaller cross section, the flow will simply bend away sidewards. The second reason is that you want to make yet engines without burning fuel. You only get air through a narrowing channel if you create a pressure difference first. This pressure differerenc results in a force opposite to the direction of rotation and so this force has the same direction as the airfoil drag. It is like driving your bike with a motor which is powered by a generator driven by the wheels. The third reason is that the airfoil tailing edge has a large part for which it isn't sharp. This causes a lot of airfoil drag. This negative effect of the larger airfoil drag will be rather strong.

You have to realise that the driving force F of a blade section is caused by the difference of the component of the lift in the direction of rotation and the component of the drag opposite the direction of rotation (see report KD 35 figure 3.2 + 4.4 and formula 4.13). The figures 4.5 up to 4.11 (depending on the number of blades) show that for fast running rotors, the drag lift ratio Cd/Cl is the most important reason why the real maximum Cp is lower than the Betz coefficient 16/27. So strong increase of the airfoil drag has a dramatic negative influence on the maximum Cp of the rotor.

[esposcar]

Answering this comment //Nice story but I am afraid that this won't work for three reasons. The first reason is that the law of Bernoulli is only valid for a tube. The funnel which you have created is open at one side so instead of flowing in the direction of the smaller cross section, the flow will simply bend away sidewards.//You forgot that the air will impact the blade with an inclination so it will not spread as the vector force will not impact the surface blade perpendicular. I do not see it going upwards or sidewards the funnel. It is also important that you try to visualize that another reason why the air will not bend bend away sidewards is because there is air pushing to come inside the funnel and I do not see neither the air inside the funnel trying to fly away in the same direction that the incoming air is directing. A small detail is the air impact in the blade surface inside the funnel,  which will do it at higher velocity than the air that impact the blade surface outside the funnels.

Yes, Bernoulli's principle can still be applied to an open funnel using air as the fluid, but with some important considerations.

Bernoulli's principle for air:
The principle assumes that the fluid (in this case, air) is incompressible, steady, and the flow is non-turbulent (laminar). Air is a compressible fluid, meaning its density can change with pressure and temperature, which complicates the application of Bernoulli's equation in certain cases. However, for low-speed flow or when the pressure changes are small (i.e., in situations where the compressibility effects are minimal), Bernoulli's principle can still serve as a good approximation.

Applying Bernoulli's principle to an open funnel with air:
Wide end of the funnel: The air moves more slowly here, and its pressure tends to be relatively higher.
Narrow end of the funnel: The air speeds up as it enters the narrower section. According to Bernoulli’s principle, the increase in velocity results in a decrease in pressure at this point.
In situations where the flow is not highly compressible, Bernoulli’s equation can be simplified and applied to the air flowing through the funnel. However, if the air speeds up significantly (such as in a high-speed flow), the compressibility of air becomes more pronounced, and the velocity and pressure relationship may not follow Bernoulli's principle exactly. In this case, more complex models of fluid dynamics would need to be used.

Practical considerations:
If the air is moving slowly (subsonic flow), Bernoulli’s principle provides a reasonable approximation for the relationship between velocity and pressure.
For faster (transonic or supersonic) flows, the changes in air density due to compressibility need to be considered, and Bernoulli’s principle alone would not be sufficient.
Conclusion:
For everyday situations involving low-speed airflow through an open funnel, Bernoulli's principle can be applied as a good approximation. However, if the flow speeds up significantly, especially to the point of approaching the speed of sound, compressibility effects will become more important, and Bernoulli's principle may not apply as directly.